Electrical Fire Close Call

[RoadTripper2084]

Well progress is slow but steady.  I figure I'm about 75% done the wire repairs now. Once the wires are all reconnected I plan to fire her up and build air pressure to help me find the air leak.

Here's a few pics of the "path of destruction" the shorted wire took from the fuse box on the driver's side of the coach, under the left console to the ground bar near the middle of the dash. Seems like approx. 18 wires involved at different points along the path. All 14awg, one 12awg. 

Anyone know where I can find the likely fire-retardant black expanding foam to re-seal the hole between the fuse bay and the coach?

Edited September 12, 2022 by RoadTripper2084

[Tom Cherry]

27 minutes ago, RoadTripper2084 said:

Well progress is slow but steady.  I figure I'm about 75% done the wire repairs now. Once the wires are all reconnected I plan to fire her up and build air pressure to help me find the air leak.

Here's a few pics of the "path of destruction" the shorted wire took from the fuse box on the driver's side of the coach, under the left console to the ground bar near the middle of the dash. Seems like approx. 18 wires involved at different points along the path. All 14awg, one 12awg. 

Anyone know where I can find the likely fire-retardant black expanding foam to re-seal the hole between the fuse bay and the coach?

Maybe??

this is what frequently showed up on Google

https://www.homedepot.com/p/GREAT-STUFF-16-oz-Fireblock-Insulating-Spray-Foam-Sealant-with-Quick-Stop-Straw-99053992/207077797

check it out….who knows?

[RoadTripper2084]

On 9/12/2022 at 12:20 PM, Tom Cherry said:

Maybe??

this is what frequently showed up on Google

https://www.homedepot.com/p/GREAT-STUFF-16-oz-Fireblock-Insulating-Spray-Foam-Sealant-with-Quick-Stop-Straw-99053992/207077797

check it out….who knows?

Thanks, I sources some similar stuff at the local Home Despot  (https://www.homedepot.ca/product/great-stuff-smart-dispenser-fireblock-insulating-foam-sealant-16oz/1001181677).

So I have now completed replacing all of the damaged wires.  Yay!

Unfortunately, I haven't been able to determine where the air leak is. The 1/4" hoses from the air gauge appear to be intact from what I can see. Now I have the problem that because the entire dash has been removed, I am unable to start the rig to air it up again. If I could add air I could likely find the leak via the soapy water spray method, or just by following the loudish leak sound.   I'm also unable to open the generator tray at the front which would provide access to the external air port.  I *might* be able to access it from underneath so I've ordered a Type M fitting that I'm hoping will fit.  

Otherwise I'll just proceed with re-wrapping/zip clipping the wires again as much as I can while still providing access to the air hoses, and get the dash components transferred over to my new dash plastics that I picked up earlier this summer.  Once the dash is fully connected, but not closed up/mounted, I should be able to start the engine and then find the air leak.

I'm open to any suggestions on alternatives to getting air into the 1/4" hoses to find the leak.  Do you think shooting air out of my portable compressor into the open end of the line would be enough pressure to hear and see the leak further down the hose?

 

[jacwjames]

My rig has a connector next to the generator I could hook an external air source to, this is used by tow trucks to air the rig to be able to tow. 

I would think your rig would have a similar connection. 

[jacwjames]

I'm not sure where the wires that melted/burned are in relation to the air lines but on my coach there is a large plastic cover on the firewall in front of the steering column.  This cover covers up the air lines that go to the brake pedal but also have the air lines for the dash air gauge, I believe there are 2 lines for the gauge since it shows front and rear pressure.  There is also a supply line to the park brake.  My guess it is either the dash air gauge line or the park brake line.    All the lines are a different color, attached is a air schematic that might help you identify which is which!  It matched what I have pretty darn close. 

If you have the plastic cover similar to mine it might give you access to be able to listen for the leak after you pressurize the system. 

Air system roadmaster chassis.pdf

[Tom Cherry]

15 hours ago, jacwjames said:

My rig has a connector next to the generator I could hook an external air source to, this is used by tow trucks to air the rig to be able to tow. 

I would think your rig would have a similar connection. 

It SHOULD.  BUT....you need to check the FITTING.  MOST of these were a special Automotive "T" Style.  Lowes sells the Quick Disconnect for them. NOW....CAVEAT.  You need to use a large compressor or one with a large reservior.  Let the compressor come ON.  Then build up pressure.  Then turn it off and drain the tank.  Repeat.  You want to have as LITTLE moisture in the compressor system as you can get.  Otherwise, you are putting WET air into the system. NOW, odds are and Frank will correct me, the male fitting or the AIR UP FOR BRAKE RELEASE line goes to the WET Tank.  After you find your leak....and restart the engine.  DO NOT HIT THE BRAKES OR DO ANYTHING.  After it airs up....then drain all THREE fittings.  May be TWO in the FRONT and one in the REAR or ALL (my Camelot) up front.  I would air up....and bleed them at least TWICE.  OVERKILL....yes, but you want to purge out any moisture. Use the rig for a few trips and then repeat.  

You should be good to go....

Good Luck,

[RoadTripper2084]

On 9/20/2022 at 6:46 AM, jacwjames said:

I'm not sure where the wires that melted/burned are in relation to the air lines but on my coach there is a large plastic cover on the firewall in front of the steering column.  This cover covers up the air lines that go to the brake pedal but also have the air lines for the dash air gauge, I believe there are 2 lines for the gauge since it shows front and rear pressure.  There is also a supply line to the park brake.  My guess it is either the dash air gauge line or the park brake line.    All the lines are a different color, attached is a air schematic that might help you identify which is which!  It matched what I have pretty darn close. 

If you have the plastic cover similar to mine it might give you access to be able to listen for the leak after you pressurize the system. 

Air system roadmaster chassis.pdf 1006.92 kB · 9 downloads

Thanks Jim.

I can access the brown and yellow lines all the way into the floor passthrough, and if need be, under the coach to the tank(s).  But there was no leak sound outside the coach, and a loud hissing sound inside.  I was pretty sure that the leak was coming from the yellow line going to the air gauge, from the last time I had it aired up, as I could feel air coming out from the protective shroud around the air line. I was expecting to find an obvious spot where the hot wire had melted into the line, but have not. 

I think I'm going to proceed with re-assembly of the dash, so long as I can still access the air lines, and then air it up from the engine compressor (Plan A).

 

[Guest Ray Davis]

Ken can you see the air lines where they attach to the gauge?   I think the lines are a push on connector.  There was a thread on IRV2 where that connector broke I'm not sure how they resolved the broken piece.  Why not inspect that area before reassembling just to be sure?

[RoadTripper2084]

23 hours ago, Ray Davis said:

Ken can you see the air lines where they attach to the gauge?   I think the lines are a push on connector.  There was a thread on IRV2 where that connector broke I'm not sure how they resolved the broken piece.  Why not inspect that area before reassembling just to be sure?

Jim, yes I can follow the lines from the gauge to the floor in the front drivers corner. The connectors are fine, when it was connected to the gauge and aired up there was no leak at the gauge, but seemed to be further down closer to the floor. The leak sound would change if I flexed the hose, which is making me think it might actually be in the section that goes through the floor. I guess I could just replace the line from under the floor to the gauge, not too sure how difficult it will be to run a new line through the floor opening.  

[RoadTripper2084]

Bit of an update.

I wrapped up the wire repairs, re-wrapped and zip-tied the bundles along the dash to the floor and into the outside fuse bay.  Spray-foamed the opening between the fuse-bay and the side console. I also cleaned up the ground connections for the ground bar and re-mounted it to the dash.

Then I started attaching a few connectors to the dash and console components until I got to the point where I could start the engine again. Once I achieved that, it was simple to locate the air leak, with the protective wrap removed from around the air lines.  It was right in front of my eyes the whole time!  Lines were touching the melting wire right where it joined the ground bar in the middle of the dash.  

 

It turns out that only the brown hose was leaking, pin-hole from the melting, as you can see. It's amazing how air and sound can travel, with the wrap still on the lines I could have sworn that it was the yellow line leaking, and the that the source was near the floor in the corner.  🤷‍♂️

Once I found the brown hose leak I inspected the yellow and could see similar damage, but as of yet no actual leak. So all I had to do was cut out the small sections that were damaged and install a push-on joiner to re-join each hose to itself. Leak fixed.  

What remains to do is to re-install the front dash framing and then the dash and side consoles themselves. As part of that I have new plastics for both, so I need to transfer each dash component/sub-module to the new plastics first.  Unfortunately, I just realized that the new plastics have the wrong size cutouts for every toggle button, they are for the smaller sized buttons.  😞

Old on left, new on right. You can see where I enlarged the end hole already, testing various methods. Fortunately the rough edge is covered by the button when it's installed.

I am going to attempt to very carefully enlarge the button holes myself using a plastic cutting disc on my dremel...

 

[dl_racing427]

11 hours ago, RoadTripper2084 said:

Bit of an update.

I wrapped up the wire repairs, re-wrapped and zip-tied the bundles along the dash to the floor and into the outside fuse bay.  Spray-foamed the opening between the fuse-bay and the side console. I also cleaned up the ground connections for the ground bar and re-mounted it to the dash.

Then I started attaching a few connectors to the dash and console components until I got to the point where I could start the engine again. Once I achieved that, it was simple to locate the air leak, with the protective wrap removed from around the air lines.  It was right in front of my eyes the whole time!  Lines were touching the melting wire right where it joined the ground bar in the middle of the dash.  

 

It turns out that only the brown hose was leaking, pin-hole from the melting, as you can see. It's amazing how air and sound can travel, with the wrap still on the lines I could have sworn that it was the yellow line leaking, and the that the source was near the floor in the corner.  🤷‍♂️

Once I found the brown hose leak I inspected the yellow and could see similar damage, but as of yet no actual leak. So all I had to do was cut out the small sections that were damaged and install a push-on joiner to re-join each hose to itself. Leak fixed.  

What remains to do is to re-install the front dash framing and then the dash and side consoles themselves. As part of that I have new plastics for both, so I need to transfer each dash component/sub-module to the new plastics first.  Unfortunately, I just realized that the new plastics have the wrong size cutouts for every toggle button, they are for the smaller sized buttons.  😞

Old on left, new on right. You can see where I enlarged the end hole already, testing various methods. Fortunately the rough edge is covered by the button when it's installed.

I am going to attempt to very carefully enlarge the button holes myself using a plastic cutting disc on my dremel...

 

Look on the bright side, it's a lot easier to make a hole bigger than smaller. 😉

[RoadTripper2084]

Well I'm pleased to report that this repair job is nearly complete! 😅

Installing the replacement dash and console plastics turned out to be a much bigger effort than I was anticipating. Apart from having to hand-cut each button hole larger there were several other holes that were drilled backwards, or mirrored from the correct positions (must have had the template upside down?), so I had to field correct those, fortunately in each case the original holes were hidden after final installation.

At this point everything is connected, but the dash, console, etc. is not secured back in place just yet to allow for access.  The coach drives, and I was able to adjust my speedometer to be accurate for the first time since owning it.  I added an additional ground wire to the dash instruments as well, and that also seems to have solved an issue I had with the tach and speedometer randomly jumping to higher values and later returning to closer to correct ones as well as an issue I had with the temp. gauge jumping up a bit when the lights were on.  😎

The big news is that everything works again!

...except for the top front clearance lights. 😞

The rear clearance lights work correctly.  Based on the wiring diagram, it appears the the front and rear clearance lights combine in the power distribution / fuse bay below the driver's seat.

 

This would indicate that everything "up circuit" from there is working fine (ECC switch, fuse, etc.).

The black wire with the green zip tie on it is the "bad" one that I think is for the front lights. When I test the two black wires with the lights on, the other one (with no zip tie) clearly acts as a ground to the 12v at the Clearance Lights post, but the zip-tied wire does not, and also does not "buzz" to ground like the working wire does.

So it would appear that I have a simple break or misconnection on my front clearance light circuit. 

It's possible that I cut the wire meaning to replace it and simply missed it and forgot to connect it. 

The other thing that occurs to me is that I stuffed a bunch of fiberglass insulation in the top cap earlier this summer, it's possible that in doing so I disconnected a wire on one of the clearance lights at that time and they haven't worked since then. Being summer we haven't needed to use the lights so could have gone undetected.

So I'm faced with a choice of two unpleasant options, either I cut open all my nicely bundled wires beside the driver's seat again and try to trace the bad black wire all the way to the front pillar, or I try to remove the fiberglass insulation that I wedged tightly in some cases into the top cap to see if I can gain access to the clearance lighting circuit there.

 

[dandick66]

You have made a lot of progress and done a great job.  I’m a little confused with your descriptions and the photos.  Is TS1 (circled in the top photo) the same part that is circled in the bottom photo?  If so, the wires are supposed to be red, and hot (+12v). If you follow the wires in the top photo, you’ll see the ground is a white wire.  
                                     
If you remove the zip tied wire, do the rear lights work?  Is the connection where the two wires are connected ground or hot? 

As far as figuring out exactly where the problem/disconnect is, I would look at the easier area first.  In your case, I don’t know if that’s at the wire bundle or the cap where you stuffed insulation.

Good luck. 
 

[RoadTripper2084]

8 hours ago, dandick66 said:

You have made a lot of progress and done a great job.  I’m a little confused with your descriptions and the photos.  Is TS1 (circled in the top photo) the same part that is circled in the bottom photo?  If so, the wires are supposed to be red, and hot (+12v). If you follow the wires in the top photo, you’ll see the ground is a white wire.  

Thanks, it's been a process for sure.  Re: TS1, well, that's my assumption. I also noticed the color discrepancy, but then I saw that in the wiring diagram once the red wires got to the first set of clearance lights they reverted to black wires, so I supposed the factory might have just stuck with the black all the way to the junction? Guessing here.

8 hours ago, dandick66 said:

If you remove the zip tied wire, do the rear lights work?  Is the connection where the two wires are connected ground or hot? 

Yes, with the zip tied wire removed, the rear lights still work. The two wires are meant to be "hot".  If I disconnect them from the junction and put my meter positive on the right side screw of the junction (incoming wire) and the negative lead on the working black wire, it shows 11.5v.  However, if I do the same on the zip-tied "non-working" wire, I get no voltage (aka, the zip-tied wire isn't grounded). 

I'm leaning toward removing the insulation batts immediately behind the CRT TV cabinet (EZ access) to see if I can find one or more clearance lights. The wiring diagram makes it look like the black wire should feed into the top left light, which I *might* be able to get to via the TV cabinet. If I can find that I can test for continuity from the zip-tied end of the wire to the light end and that will tell the tale in terms of if the problem is in that wire or further down the circuit for the lights.

 

[dandick66]

Interesting… I thought the voltmeter had to be connected in parallel for it to read voltage.  From what you described, you’ve connected it in series, like an ammeter.  
 

This has me scratching my head.  I hope you’re able to get that insulation out and look at the wires.  Judging from the diagram, the ground and power connections start at the driver’s side.  Since the first light isn’t working, the problem has to be at or downstream from the point.  Good luck.

[MyronTruex]

I think you might be led astray using the voltmeter. Your description of how you are testing things is unclear to me. 

 

For the time being, give the voltmeter a rest and grab a simple 12 volt test light. Not a fancy one that needs any power. A very cheap one that has a light bulb inside if possible. Not an LED one. You need a light bulb load for testing.

Find a reliable ground for the tester. Poke the tester onto a known 12 volt circuit and it should shine brightly.

Now go to the post where the wire tie wire is connected to. Check the left side of that terminal strip and the right side. Post the results. 

Without a very close up I am going to make an assumption that that terminal strip is just that. A simple dumb place to connect wires. Whatever is on the left should also be on the right, weather it is a ground or 12 volts.

Test this theory on several of the places.

If you find it is such, then the place where the wire tied wire goes should have identical voltages or ground on each side 

If there is voltage, the light will shine of course. 

IF the post is at ground potential. Your light will not shine but you also will not know if that is actually a good ground. 

Find one of the places that has a good 12 volt source by probing around with the tester. Then take the alligator lead and put it on the 12 volt spot. Touch your probe to a known good ground and  it should light. Move over to the terminal spot where the test light did not light up and touch that spot. IF the tester lights up this indicates that is a ground. 

I hope this is clear and if you need me to walk you through it I would be glad to do so. 

You have a great diagram and understanding how the lights should work but I think your testing methods are a bit suspect.

Been doing this for over 50 years now and have helped many over the phone.

 

Hope this does not come too late to help.

 

 

 

Adding one thing about voltmeter. IF you put one in series it can easily read full battery potential but does not tell you squat about its effectiveness.

[RoadTripper2084]

Thanks for the tips guys, I really appreciate all the help I can get.

7 hours ago, dandick66 said:

Since the first light isn’t working, the problem has to be at or downstream from the point.

Not necessarily, because the ground wires on the lights are daisy-chained as well, so if the ground connection is broken none of the lights will light. 

4 hours ago, myrontruex said:

I think you might be led astray using the voltmeter. 

It wouldn't be the first time. 😉

4 hours ago, myrontruex said:

Check the left side of that terminal strip and the right side. Post the results. 

Without a very close up I am going to make an assumption that that terminal strip is just that. A simple dumb place to connect wires. Whatever is on the left should also be on the right, weather it is a ground or 12 volts.

This is correct, the terminal is just a connection between the left-right side.

Here are some diagrams to better explain how I tested for voltage.  First I disconnected both the wires on the left side of the terminal, which I believe are the wires to the front and rear clearance lights (these are on the right side of the terminal in the wiring diagram).

Then I put my red meter's lead on the terminal and the black lead on each wire (individually) and recorded the voltage present.

Rear Lights (rear lights work but go out when this wire is disconnected)

 

Front Lights (not working when wire is connected)

 

I hope that makes things a bit clearer.

I notice on the wiring diagram that the front light wire goes through a connector?, M13 or maybe M1.3?  pin 9.  I think I'll see if I can find that connector, as if I can I can use it as another test point to see if the "bad" wire has continuity from the terminal to the connector or not. If it does not, that tells me the wire is cut between the two.

Had to winterize the rig as we're expecting some "seasonal" temps this weekend dipping down to 20F overnight and into next early next week, so might be a week or two before I can get back to this.

 

[RoadTripper2084]

On 10/18/2022 at 4:14 PM, RoadTripper2084 said:

Had to winterize the rig as we're expecting some "seasonal" temps this weekend dipping down to 20F overnight and into next early next week, so might be a week or two before I can get back to this.

 

...make that 6 cold miserable months.

Okay, I removed all the insulation I had behind the top front cabinets to get access to the non-working running lights there, definitely no +12v hitting that string. I was able to see that the black wire from the electrical bay would break continuity when the "Truck Flasher" button was pressed, so that gave me confidence that the problem wasn't in my wire-patching, at least not directly.

Frankly I was out of ideas and time, so resigned myself to not having working front clearance lights and set out to finally re-assemble my dash. Not a huge issue in these parts since it's light out till 10pm into July, so actually driving in the dark is only a possibility in the fall.

...but wouldn't you know it. While I was vacuuming out the bottom of the dash area I stumbled across a connector with an exposed red wire .5 inch away from it, hiding under the other bundles! At some point my jostling of the wire bundle must have caused this wire to pull out of its pin crimp.  I repaired the crimp and my front clearance lights are working! 

So that was dumb luck more than anything I did, but considering the hours that I spent trying to find the problem, I'll take it as a win!  🙂