Electrical Fire Close Call

[RoadTripper2084]

Well we were either extremely lucky or unlucky (depending on your view of how full the glass is I guess) last weekend.

After a very pleasant 60 mile drive down the highway to our campground all hell broke loose.  A block before pulling into the campground I started to here a loud hissing sound from under the front dash that I hadn't heard before, then just as we were pulling up to stop at the front gatehouse acrid smoke started to pour out of edges of the left side of the front dash. Electrical fire!  

I quickly got everyone out of the coach, shut it down, and disconnected the batteries via the disconnects in the rear engine bay. After a few minutes things seem to settle down, no more smoke, though I had a new air leak under the dash.  I was able to fire it up and drive to a large parking lot about 50 yards away. There I started to disassemble the dash and open the driver's side fuse compartment.

Long story short, there was a set of 3 wires that had been dangling wrapped loosely around other wires in the fuse compartment that had basically disintegrated with most of their insulation melted off. These wires were not connected to anything in the fuse compartment (was this way when I bought the coach last fall), but had somehow shorted out and melted.

It's amazing how fast you can figure out how to remove the dash cover when you think there might be a fire smouldering under it. 

Once I got the dash partially off I was also able to see one white wire on the ground bar completely melted, along with a second wire attached to the same ground port. 

At the time, I pulled all the fuses for stuff we didn't need to drive the coach, and disconnected the burnt ground wire from ground. The burnt wire in the fuse compartment read 0v and no continuity to ground, either.

We were able to complete our camping weekend and drive home without further incident. Fortunately, the air leak under the dash was slow enough to allow the compressor to more than compensate so we could drive.

Now I've completely removed the dash, dashboard, and side control panel to gain better access. I'm attempting to trace the damaged wires so I can determine which other wires were affected and repair them, and hopefully find the source of the short.

The wires in the fuse compartment were not connected on this end. Appears to be 2 live brown wires crimped together on the end, and one white ground wire. These all melted together or lost their insulation completely. They shared a plastic wire loom with the generator slide switch wires up and into the opening through the floor.  The loom was completely melted but through some miracle the generator slide wires were not harmed. Even up through the floor opening there is only minor scorching on the surrounding wires, which appear to be fine.

I was able to pull this wire up through the floor opening into the drivers side compartment (where the transmission controls, etc. live) and discovered that they actually seem to disappear under the floor somehow, and do not actually run through the compartment above the floor. Nor do they run under the coach. So this remains a mystery and I'm not sure how to proceed tracing these, they seem to be solidly routed into the floor.

Under the dash, I was able to find two toasted ground wires. They both shared the same ground port, so one really toasted white wire, and one partially toasted green wire.

Tracing that wire back toward the driver's side of the dash, there are partially melted wires surrounding it inside the middle of the bundle. Likely different wires at different locations just based on which wires were closest to the melting wire at that point.

So far I've been able to trace the melted ground wire to the bottom left corner where it drops from the dash and runs down to the floor, and then continues on to the opening through the floor and the fuse box.  I have NOT been able to get enough access to see if the damage continues around the bend and to the opening yet, just as far as the middle of the drop to the floor.  

I was also able to determine that the yellow 1/4" air line going to the air gauge is the one leaking, and seems to be coming from that same front drivers corner where the wires and the air lines go through the same rubberized metal bracket. Though again, due to tight access I wasn't able to actually pull things apart enough to see the leak/damage. At this point I have to assume the hot ground wire burned a hole through the air line.

Sorry for the really long post, but I wanted to share everything I've found so far.

So questions for anyone who has experience with this sort of thing:

1. It seems like I should be able to replace the damaged wires by either patching in new wires for sections where they are damaged, or even just running new wires the length of the damaged section.  Opinions?

2. What if I can't determine where the short occurred? Any advice or tips is appreciated.

3. I'm having a bear of a time accessing the front left corner under the dash, the steering column is in the way. Would it be sane to remove the steering column? Probably just the U-joint and then maybe 4 large bolts holding it to the floor (plus wires)?

Obviously a very close call we could have lost the whole rig. I feel we actually were very fortunate the way things have turned out thus far, but really wanting to make solid repairs to avoid similar issues in the future.

[Just Jim]

Yes, you were very fortunate!!!  Just sending well wishes on the repair, I am not the electrician on this forum.  I have electrical gremlins I've been chasing on mine for years.

[jacwjames]

Yes you were lucky.  When I was chasing a problem (mine was self inflicted). and I had a heck of a time trying to chase wires under the dash and the drives side console. 

Not sure if a wire tracer would work under these circumstances considering the condition of the wires but you could give it a try.  Trace every burnt wire to see where it goes/comes from.  It might narrow down the scope of your work.

Good Luck

 

[Tom Cherry]

Comments….from some auto and maintenance “smoked” scorches. You sound more than up to the task….so I hope you don’t take this as talking down.

get a small flexible camera and use your phone, or even better an iPad or tablet.  They are wireless so all you need is a usb or some have a rechargeable battery.  I chose “best seller” or Amazon’s choice…less than $50.  You will be amazed.  They have an LED on them for light.

next up…a nice high quality ratcheting crimper….they are the nuts.  And a basket full of butt splices and a lot of #14 & #16 stranded hookup wire.

finally a Brother labeler.  Get a variety pack of the tape cartridges with several colors.  Then when you cut and use the old wire as a snake….to pull the new wire in, you put a label or number or alpha code on each end.  Do one at a time.

probably a good pair of SS Forceps….locking with a long tiny nose.  I use them on most “delicate” wiring jobs….

a pair of “precision” cut wire (side cutter or diagona)  to get clean, and easy to get into a butt splice connector.

as to pulling the steering column.  Do some googling. Someone has done that before….again, that seems within your skill set.

photo and document..  blue painters tape and a sharpie are your friend.  If you are concerned, as I would be, and can’t trace or find the culprit…then pull the offending wires out.  You may want to use some inline fuses on the power leads you have to splice…..just put them in accessible places and label.

that’s about it. Keep us posted.

 

[Ivan K]

Hopefully you have or can get wiring diagrams. It won't solve everything but certainly helps with color coded wires. A tracer will at least help to figure out in which bundle each effected wire leaves the location and which direction it branches out, then the color coding and more tracing takes place at the other end. That's IF you want to find where it goes and test that device for short before turning it up.  And the steering surround should be removable to get visibility, I have been there and still hurt. Not fun but you'll figure it out. Good luck!

[On_the_road]

45 minutes ago, jacwjames said:

Not sure if a wire tracer would work under these circumstances considering the condition of the wires but you could give it a try.  Trace every burnt wire to see where it goes/comes from.  It might narrow down the scope of your work.

 

 

I bought a Klein Tools tracer to help me follow wires behind the dash and in the fuse boxes.   Unfortunately, it was no help.   The signal seems to couple into adjacent wires, and at the same time the signal weakens in the correct wire.   Within one foot you can't tell which wire the signal is on.   The tracer may work well in AC wiring in a house where the wires are spaced apart, but it does not work when all the wires are in a bundle.

 

 

[Jim Pratten]

A possible root cause to consider is you have a poor ground connection on a larger conductor.  A smaller conductor may have served as an alternate current path exceeding its capacity. The larger conductor would show no signs of damage in this senecio. I haven’t dug into my dash yet but my drawings show a couple ground buss bars inside the firewall. I’d look for and tighten/reconnect any suspect grounds.  

Good luck!

[MyronTruex]

You did a great job thinking to turn the battery switches off.

It looks to me that someone used a heavy butt connector to combine a couple of wires. This is fine but if left unsecured or it gets loose it may have been free to make contact with a solid/heavyily fused 12 volt source. You have plenty of welding power right there from the batteries.

Putting that virtually uncontrolled amount of power on a wire that may have been a ground wire would have done exactly as shown and worse. You are lucky.

The wire may have burned so severely that it opened up and quit providing the short to ground.  

It might not have been the butt connector. It could have been a wire chafing that caused the issue. 

I experimented in early days and used a simple light wire across a 12 volt battery to demonstrate safety to my technicians. The wire would evaporate quickly.

So wearing a watch or wedding ring around a 12 volt system is very dangerous.

I would clean up the wires as you are doing with pictures prior to the task. Take it one at a time and you may find that wire is a ground. 

You may not need a diagram. Just fix everything in sight and try to find out if something does not work. 

You might consider taking the captains chair out during this repair for better, more comfortable access to things.

Cutting and splicing melted wires is fine if done with proper crimpers and commercial quality connectors. 

Be sure to tug hard on each connection after crimping.

 

[dl_racing427]

9 hours ago, Jim Pratten said:

A possible root cause to consider is you have a poor ground connection on a larger conductor.  A smaller conductor may have served as an alternate current path exceeding its capacity. The larger conductor would show no signs of damage in this senecio. I haven’t dug into my dash yet but my drawings show a couple ground buss bars inside the firewall. I’d look for and tighten/reconnect any suspect grounds.  

Good luck!

That's an idea I hadn't considered.  Makes perfect sense though.
Way to think outside the box Jim. 👍

[dandick66]

16 hours ago, RoadTripper2084 said:

Well we were either extremely lucky or unlucky (depending on your view of how full the glass is I guess) last weekend.

After a very pleasant 60 mile drive down the highway to our campground all hell broke loose.  A block before pulling into the campground I started to here a loud hissing sound from under the front dash that I hadn't heard before, then just as we were pulling up to stop at the front gatehouse acrid smoke started to pour out of edges of the left side of the front dash. Electrical fire!  

I quickly got everyone out of the coach, shut it down, and disconnected the batteries via the disconnects in the rear engine bay. After a few minutes things seem to settle down, no more smoke, though I had a new air leak under the dash.  I was able to fire it up and drive to a large parking lot about 50 yards away. There I started to disassemble the dash and open the driver's side fuse compartment.

Long story short, there was a set of 3 wires that had been dangling wrapped loosely around other wires in the fuse compartment that had basically disintegrated with most of their insulation melted off. These wires were not connected to anything in the fuse compartment (was this way when I bought the coach last fall), but had somehow shorted out and melted.

It's amazing how fast you can figure out how to remove the dash cover when you think there might be a fire smouldering under it. 

Once I got the dash partially off I was also able to see one white wire on the ground bar completely melted, along with a second wire attached to the same ground port. 

At the time, I pulled all the fuses for stuff we didn't need to drive the coach, and disconnected the burnt ground wire from ground. The burnt wire in the fuse compartment read 0v and no continuity to ground, either.

We were able to complete our camping weekend and drive home without further incident. Fortunately, the air leak under the dash was slow enough to allow the compressor to more than compensate so we could drive.

Now I've completely removed the dash, dashboard, and side control panel to gain better access. I'm attempting to trace the damaged wires so I can determine which other wires were affected and repair them, and hopefully find the source of the short.

The wires in the fuse compartment were not connected on this end. Appears to be 2 live brown wires crimped together on the end, and one white ground wire. These all melted together or lost their insulation completely. They shared a plastic wire loom with the generator slide switch wires up and into the opening through the floor.  The loom was completely melted but through some miracle the generator slide wires were not harmed. Even up through the floor opening there is only minor scorching on the surrounding wires, which appear to be fine.

I was able to pull this wire up through the floor opening into the drivers side compartment (where the transmission controls, etc. live) and discovered that they actually seem to disappear under the floor somehow, and do not actually run through the compartment above the floor. Nor do they run under the coach. So this remains a mystery and I'm not sure how to proceed tracing these, they seem to be solidly routed into the floor.

Under the dash, I was able to find two toasted ground wires. They both shared the same ground port, so one really toasted white wire, and one partially toasted green wire.

Tracing that wire back toward the driver's side of the dash, there are partially melted wires surrounding it inside the middle of the bundle. Likely different wires at different locations just based on which wires were closest to the melting wire at that point.

So far I've been able to trace the melted ground wire to the bottom left corner where it drops from the dash and runs down to the floor, and then continues on to the opening through the floor and the fuse box.  I have NOT been able to get enough access to see if the damage continues around the bend and to the opening yet, just as far as the middle of the drop to the floor.  

I was also able to determine that the yellow 1/4" air line going to the air gauge is the one leaking, and seems to be coming from that same front drivers corner where the wires and the air lines go through the same rubberized metal bracket. Though again, due to tight access I wasn't able to actually pull things apart enough to see the leak/damage. At this point I have to assume the hot ground wire burned a hole through the air line.

Sorry for the really long post, but I wanted to share everything I've found so far.

So questions for anyone who has experience with this sort of thing:

1. It seems like I should be able to replace the damaged wires by either patching in new wires for sections where they are damaged, or even just running new wires the length of the damaged section.  Opinions?

2. What if I can't determine where the short occurred? Any advice or tips is appreciated.

3. I'm having a bear of a time accessing the front left corner under the dash, the steering column is in the way. Would it be sane to remove the steering column? Probably just the U-joint and then maybe 4 large bolts holding it to the floor (plus wires)?

Obviously a very close call we could have lost the whole rig. I feel we actually were very fortunate the way things have turned out thus far, but really wanting to make solid repairs to avoid similar issues in the future.

Looking at your first photo… it looks like there was chafing near the zip tie.  Is the insulation intact on the large red cable?  Also, follow that large red cable and it looks like it is going to a solenoid relay.  It looks like the top terminal on the solenoid is touching the wire loom.  Is the wire loom intact?  It looks like maybe the loom rubbed through and hit the solenoid terminal.  You said you pulled the fuses for all the stuff you didn’t need to drive.  You might want to get a meter and check each of those connections where you removed the fuse.  Alternatively, you could start replacing the fuses and see if one blows.  Even if they don’t blow, test the device associated with the fuse.  Since you said the wires weren’t connected to anything in the fuse panel, I’m a little confused.  Do you have any aftermarket devices that may have been wire into the system?  
Glad you are safe and were able to prevent further damage.

[RoadTripper2084]

14 hours ago, Tom Cherry said:

Comments….from some auto and maintenance “smoked” scorches. You sound more than up to the task….so I hope you don’t take this as talking down.

get a small flexible camera and use your phone, or even better an iPad or tablet.  They are wireless so all you need is a usb or some have a rechargeable battery.  I chose “best seller” or Amazon’s choice…less than $50.  You will be amazed.  They have an LED on them for light.

next up…a nice high quality ratcheting crimper….they are the nuts.  And a basket full of butt splices and a lot of #14 & #16 stranded hookup wire.

finally a Brother labeler.  Get a variety pack of the tape cartridges with several colors.  Then when you cut and use the old wire as a snake….to pull the new wire in, you put a label or number or alpha code on each end.  Do one at a time.

probably a good pair of SS Forceps….locking with a long tiny nose.  I use them on most “delicate” wiring jobs….

a pair of “precision” cut wire (side cutter or diagona)  to get clean, and easy to get into a butt splice connector.

as to pulling the steering column.  Do some googling. Someone has done that before….again, that seems within your skill set.

photo and document..  blue painters tape and a sharpie are your friend.  If you are concerned, as I would be, and can’t trace or find the culprit…then pull the offending wires out.  You may want to use some inline fuses on the power leads you have to splice…..just put them in accessible places and label.

that’s about it. Keep us posted.

 

Thanks for all the support guys. 

I've got all those items except the rated wire and connectors!  I forgot all about the camera, it's sitting in a cabinet in the coach. I'll use that to see if I can figure out where the burnt wires that appear to go into the floor are going.

13 hours ago, On_the_road said:

I bought a Klein Tools tracer to help me follow wires behind the dash and in the fuse boxes.   Unfortunately, it was no help.   The signal seems to couple into adjacent wires, and at the same time the signal weakens in the correct wire.   Within one foot you can't tell which wire the signal is on.   The tracer may work well in AC wiring in a house where the wires are spaced apart, but it does not work when all the wires are in a bundle.

Thanks, real-world feedback is invaluable.

Fortunately? it appears the most of the damage is along one long, thick harness across the dash and down to the fuse panel outside. I think I'm going to try to make a list of every damaged wire I can identify along the length of it and then just run a small bundle of new wires the length of the damaged area to replace them.

Thoughts on repairing the 1/4" air line? I believe somewhere I saw you can by a splice kit type of thing with push-on connectors?

But first I need to get into that corner...

10 hours ago, Jim Pratten said:

A possible root cause to consider is you have a poor ground connection on a larger conductor.  A smaller conductor may have served as an alternate current path exceeding its capacity. The larger conductor would show no signs of damage in this senecio. I haven’t dug into my dash yet but my drawings show a couple ground buss bars inside the firewall. I’d look for and tighten/reconnect any suspect grounds.  

Good luck!

Yeah, I'm really hoping the root cause is obvious when I find it. There's no indication that the dangling wires contacted the giant 2/0 positive battery terminal near them in the fuse box. At the time we had the stereo running loud, generator on, a/c units on, dash fans on...

I believe that some of the damaged wires are involved with the stereo system. After the incident the Sony deck was showing some very odd glitches on the LCD display (bad ground?). That's when I pulled all the related fuses. Also, this coach has slots at the bottom of the fuse panel for two amplifies but no wires running to them. The amplifiers are installed under the dash though, so going to need to take a hard look at the stereo circuits to make sure it's properly fused, etc.

 

6 minutes ago, dandick66 said:

Looking at your first photo… it looks like there was chafing near the zip tie.  Is the insulation intact on the large red cable?  Also, follow that large red cable and it looks like it is going to a solenoid relay.  It looks like the top terminal on the solenoid is touching the wire loom.  Is the wire loom intact?  It looks like maybe the loom rubbed through and hit the solenoid terminal.  You said you pulled the fuses for all the stuff you didn’t need to drive.  You might want to get a meter and check each of those connections where you removed the fuse.  Alternatively, you could start replacing the fuses and see if one blows.  Even if they don’t blow, test the device associated with the fuse.  Since you said the wires weren’t connected to anything in the fuse panel, I’m a little confused.  Do you have any aftermarket devices that may have been wire into the system?  
Glad you are safe and were able to prevent further damage.

I do not believe there is any physical damage to the large red cable, I will take another look though. Also, the loom was not contacting the solenoid relay terminal, though I will inspect the terminal for any indications of contact. The photo is deceiving there was several inches of space between them.

Good idea to check for shorts now between the fuse terminal circuits - will do that.

Well it's an 1997 coach, previous owners have made a few undocumented changes over the years. These wires in the fuse box had been wrapped and dangling there since I got it. I could have swore I had pictures of it before the incident but can't find them now. Wanted to double check what the white ground wire was terminated with. Under the dash, there are quite a few other wires that have been cut and "capped" with a butt splice. I'll be cleaning all those up too with a proper terminator.

 

[Tom Cherry]

Well....at least you got several "coaches" or "trainers" in your corner.  Go out there and make us proud...

Seriously.....you have brought up all the salient points and folks have given you some good tips and such.  Now the REAL job begins....but I think you will take care of it...and install some more protection, when you sort it out.....or remove the abandoned circuit and GOOD riddance.

Good Luck.  Keep us posted....

[jacwjames]

If you have enough slack in the air line you should be able cut out the bad section and use a push to connect fitting.  Take the piece you cut off to a large auto parts store or truck repair and the may have it.  I actually recently bought some of these to carry as spare along with sections of the tubing. 

 

I have found several wires loose in various places that had no caps at all on them.   One that surprised me was the large #10 awg wires I found on top of my black tank just cut and coiled up.  After some testing I found these were for the "optional" tank pad heaters that were never installed.  The wires were hot anytime the small wet bay heater was working.  I went ahead and used them and installed tank pad heaters.  I guess from now on I'll try to identify and test to see if they are hot. 

[Jim Pratten]

Another thought.

My preferred troubleshooting approach is to recreate the problem and make one “fix” at a time until problem is corrected. ***For your situation it comes with some risk.***
You’d have to plug fuses back in and bring on the systems that were running when the event started. After the source of the over current is identified and corrected, I’d start reworking all the damaged and abandoned circuits. 

[RoadTripper2084]

Another 3 hours cutting zip ties and removing metal wire guides.  I tried to use the snake camera thing to see down the hole to the fuse compartment but could never get a clear shot. Then the battery died.

However, I was finally able to release the bundle in the left front corner and get to the melted wires in the back, and also determined that the brown wires from the fuse panel were just running through yet another zip tie right in the middle of the floor passthrough that I had missed. This means that I can trace the burnt wires along their entire path from the source in the fuse compartment to the ground bar under the center of the dash.  

I also found my picture of what the fuse compartment looked like before the fire. Here's a  before/after comparison for all of us amateur fire investigators:

I'm really annoyed with myself for not dealing with those wire immediately when I found them that way. Just wasn't thinking at all, figured must be okay if the previous owner left them like that.  Doh!

And the answer is:

The ground wire end moved in transit and shorted nicely into the battery positive distribution bar.  Some accidents are as predictable as if you planned them.  😞

At least I've confirmed the source of the short, owner stupidity!

So that white ground wire got hot enough to melt off all it's insulation, and even came apart in several places. This in turn melted the insulation of any wires wrapped in close proximity to that ground. The actual wires involved varies along the path of the ground from the fuse panel to the dash ground bar. You can see it got hot enough in the fuse box (due to being wrapped around itself and the brown wires several times) to blacken the large 2/0 red wire above it. I also believe that's what melted the black plastic wire wrap at the top of the compartment primarily, as flames/heat from the coiled ground wire rose up.

And closer inspection of the back of the 2/0 red battery positive wires found this nasty bit of damage, which I think was caused when the ground wire wrapped around it started to burn. This would have only made the short even worse:

I'll make another post later showing the "path of destruction" pics.

Time to order some suitable wires and supplies to begin the repairs.

Edited September 5, 2022 by RoadTripper2084

[Jim Pratten]

That’s great knowing with confidence what caused the over current.  Good job and good luck with repairs. 

[RoadTripper2084]

9 hours ago, Jim Pratten said:

That’s great knowing with confidence what caused the over current.  Good job and good luck with repairs. 

Yes it's actually a big relief to know the origin was just something foolish and not because there is some inherent wire wear issue in the coach.  After going throw all the wires I have I'm happy to report that the overall condition of the wiring is excellent, with no wear at brackets or other pinch points.  I'm going to make sure all the orphaned/cut wires are probably capped and taped too before I close things up. 

I still want to map the radio + amplifier circuits to make sure they are all properly fused, since they are no longer using the bottom fuse slots for the amplifiers in the fuse bay.

Edited September 5, 2022 by RoadTripper2084

[Tom Cherry]

14 hours ago, RoadTripper2084 said:

Another 3 hours cutting zip ties and removing metal wire guides.  I tried to use the snake camera thing to see down the hole to the fuse compartment but could never get a clear shot. Then the battery died.

However, I was finally able to release the bundle in the left front corner and get to the melted wires in the back, and also determined that the brown wires from the fuse panel were just running through yet another zip tie right in the middle of the floor passthrough that I had missed. This means that I can trace the burnt wires along their entire path from the source in the fuse compartment to the ground bar under the center of the dash.  

I also found my picture of what the fuse compartment looked like before the fire. Here's a  before/after comparison for all of us amateur fire investigators:

I'm really annoyed with myself for not dealing with those wire immediately when I found them that way. Just wasn't thinking at all, figured must be okay if the previous owner left them like that.  Doh!

And the answer is:

The ground wire end moved in transit and shorted nicely into the battery positive distribution bar.  Some accidents are as predictable as if you planned them.  😞

At least I've confirmed the source of the short, owner stupidity!

So that white ground wire got hot enough to melt off all it's insulation, and even came apart in several places. This in turn melted the insulation of any wires wrapped in close proximity to that ground. The actual wires involved varies along the path of the ground from the fuse panel to the dash ground bar. You can see it got hot enough in the fuse box (due to being wrapped around itself and the brown wires several times) to blacken the large 2/0 red wire above it. I also believe that's what melted the black plastic wire wrap at the top of the compartment primarily, as flames/heat from the coiled ground wire rose up.

And closer inspection of the back of the 2/0 red battery positive wires found this nasty bit of damage, which I think was caused when the ground wire wrapped around it started to burn. This would have only made the short even worse:

I'll make another post later showing the "path of destruction" pics.

Time to order some suitable wires and supplies to begin the repairs.

You are saving yourself a bundle.  Amazon sells a hydraulic crimper in the 65 range.  I’d get one.  I did some recabling of 2/.0 stuff.  I carry new terminals…correct wire size and terminal “hole” diameter as well.  If I ever need to, I can put on a new terminal on a 4/0 Cable or 2/0.  Just a suggestion….

[dl_racing427]

3 hours ago, Tom Cherry said:

You are saving yourself a bundle.  Amazon sells a hydraulic crimper in the 65 range.  I’d get one.  I did some recabling of 2/.0 stuff.  I carry new terminals…correct wire size and terminal “hole” diameter as well.  If I ever need to, I can put on a new terminal on a 4/0 Cable or 2/0.  Just a suggestion….

I have one of those hydraulic crimpers, from either Amazon or Ebay, and it works quite well.
Big step up from a hammer and punch. LOL

[MyronTruex]

Hopefully, no grounds in things like radios etc are damaged. Sending 12 volts with virtually unlimited supply current until the wire burns itself in half has the potential for causing more disasters but it looks as thought you came out well overall.

Have you identified what those wires were added for? I could have missed it of course. Or just forgot already. 

Thanks for sharing your adventure with such great pictures. As an ET I am always interested in something like this. 

[Guest Ray Davis]

This is a great thread, thanks to all of the posters especially Roadtripper the OP.   We can all see how lucky he was, this could have been a catastrophe.          Roadtripper has done a great job of disconnecting things, moving the coach, and locating the burned wires.

We can also see how easy it can be to get into electrical trouble with perhaps one little wire unprotected or sharing a wire or substituting a larger fuse.         I think it may have been close to the whole bundle of wires becoming involved.  Which could have been tragic.

It looks to me like the original owner picked up 12v for some device that was added.  That yellow wire was surely fused but it was too large for the added black wire.   If the black wire had it's own proper fuse it would have blown and resulted in no burned wires

 

 

[RoadTripper2084]

3 hours ago, Ray Davis said:

This is a great thread, thanks to all of the posters especially Roadtripper the OP.   We can all see how lucky he was, this could have been a catastrophe.          Roadtripper has done a great job of disconnecting things, moving the coach, and locating the burned wires.

We can also see how easy it can be to get into electrical trouble with perhaps one little wire unprotected or sharing a wire or substituting a larger fuse.         I think it may have been close to the whole bundle of wires becoming involved.  Which could have been tragic.

It looks to me like the original owner picked up 12v for some device that was added.  That yellow wire was surely fused but it was too large for the added black wire.   If the black wire had it's own proper fuse it would have blown and resulted in no burned wires

 

 

Actually, the "black wire" in this case was actually a white 14 AWG ground wire that was completely disconnected just sort of floating in space there, and that had somehow swung over and contacted and shorted against the battery-positive connection in the picture while we were driving.

I can't remember how the end of it was capped (or if it was just cut off), and I can't tell from the "original" picture I have either.  I remember looking at that bundle of wires after I purchased the coach and wondering what it was originally meant for, but didn't really occur to me at the time that it was a time-bomb the way it was just hanging in the fuse bay like that. 

So I consider this a bit of a freak accident, but one that was entirely avoidable. The best mistakes are the ones serious enough that we learn from but not so bad that they can't be overcome with a little hard work and inconvenience. 😉

 

[Guest Ray Davis]

Sorry, the burned wire you have circled looked black to me.

[RoadTripper2084]

2 hours ago, Ray Davis said:

Sorry, the burned wire you have circled looked black to me.

Well, it's black now! 😉

[BennieH]

I know several have said it but, get a high quality professional Racheting Crimpers and use commercial crimp connectors! I have a crimper that wasn't cheap years ago and it has never failed me.