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2003 Signature PCB 4 & 5 Front Run electrical issues


Moiras
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Hi Guys,

Signature 2003 here.  Awhile back this summer my pop out radio failed to pop out, the viper didn't work, then I noticed my LP EOL alarm was going off but then stopped.  I went out and bought another LP alarm but its not working.  Low and behold the CO alarm in the bedroom is not working.  So all these things were spread far apart.  I also had a lot of battery , converter, and inverter work but that was after the radio failed.  So out there in the front run box I believe these two boards are on the chassis battery disconnect switch.  When I turn the ign key on, their lights do not come on.  Checking the fuses, Im not getting any voltage except on the spare terminal.  I do not know how to use the test LED lights connection.  All the big cables coming in the box seem tight then they disappear behind the boards.  Is there another fuse next to the chassis batteries that may have caused these boards to both fail?   Where do I look next?  Thank you guys so much.

 

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In my rig that fact pattern sounds like one of the salesman switch solenoids has failed. (That happened to me a year or two ago).
 

On my salesman switch (in the rear run bay) I have two solenoids- one feeds my Domestic Fuse panel, the other feeds part of the Front Run Bay (and those circuits you were talking about). I think they are just not getting power  

I was just talking about this in the “Limited  Power” thread today (in the same section here on Monacoers)

I know we each have snowflakes- but sometimes things match up. 

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2 hours ago, Rocketman3 said:

In my rig that fact pattern sounds like one of the salesman switch solenoids has failed. (That happened to me a year or two ago).
 

On my salesman switch (in the rear run bay) I have two solenoids- one feeds my Domestic Fuse panel, the other feeds part of the Front Run Bay (and those circuits you were talking about). I think they are just not getting power  

I was just talking about this in the “Limited  Power” thread today (in the same section here on Monacoers)

I know we each have snowflakes- but sometimes things match up. 

There seems to be a run on them. We have helped two folks.  There, as stated, are two up front.  If the fail, you have mega issues.  Either purchase a 25 volt ohm multimeter (VOM) and watch one of the 250+ YouTube videos or go to any big box auto store and purchase a DC test light.  You take one lead or clip and put it to a chassis screw.  
NEXT.  You take the other lead and test.  Turn on the IGNITION SWITCH.  Touch one cable or stud on each of the two large solenoids.  There are TWO Stud on each. Both should light the light on either stud or where the large cables are connected.  If both do not light it, then on stud should.

One stud or cable is the incoming power.  So. ONE Lighting up is good.  Incoming power.  If neither has power, you have a problem and find a MH ELECTRICAL TECH.  ONE on each lights up (with ignition on), and the other does not….problem.  

Next…..look at the prints in your manual.  If the fuse to power or operate the solenoid is blown, replace.  If the fuse is good….then bad solenoid.

there should be two small wires to each.  With the ignition switch on, one of them will test OK as in getting voltage.  If neither light the light, you gor a blown fuse.

Good Luck

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Hey Rocketman,  I checked the voltage on both sides of the solenoids and they were all about 13. something volts.  This really puzzled me because while the first failure I remember happened before I had lithium batteries installed, bypassed the BIRD in the back, installed a battery charger for the chassis and installed a fast tripping breaker back there all in the rear run box, that's where they were working.

 I have since found a large red wire that may have come disconnected from a 80A circuit breaker above the 8th hole that runs across the bottom of the rear run box.  I am almost positive that is where it came from.  There is a wire that goes from the house battery disconnect switch to the 7th hole (Domestic Batt Hot) then through the 80A circuit breaker down to the 8th hole (Front Run Box Domestic Fuse Block)

The red wire that is not connected to that 8th hole goes to the bottom left big red wire in the front run box.  It appears to be unpowered.  I'll attach a diagram and a pic.  I am waiting to hear from the guys who worked on my coach before I attempt to electrocute myself!  

for some reason the pic posted upside down

 

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2004 Low Voltage High Current.pdf

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Hey Tom, I just wrote to Rocketman about the big red wire I found disconnected from the 80A breaker in the rear run box. 

But I did look for a fuse for the solenoids but couldn't find one in the back.  I checked the 2 7.5 amp CBs that were on the BIRD circuit board. They were ok.  And I got good voltage on each side of the 2 solenoids.  The Big Boy has been bypassed by taking off the green ground wire when they installed my lithium batteries.  I was also told that they bypassed the Big Boy by doing something to the #3 and #4 terminals along the bottom of the box.  Domestic Battery SW and Inverter wires respectively.

So I am almost positive the #8 hole which was supposed to have the big red wire in it that goes to the front run panel is the culprit and I will let you know what the story is with that as soon as I get the OK.

Thank you for your help with this.  I appreciate it greatly.

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One easy test to see if that wire goes where you believe it does is to use the ohm setting on your DMM (digital multimeter).  Attach another wire (ran outside of the rig) to the big red wire and then go see if you get a completed circuit at the front run bay with the  new wire and the end of the big red wire. 

it does sound like you figured it out - just test your assumptions before installing  

good luck!

Edited by Rocketman3
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Measure the wire and lug for voltage. If either has voltage you can move on to the next test. 

Grab that 12-volt test light and connect it to the large wire and then touch it to the post it came from. This puts the test light in series with the circuit. A voltmeter will not give you a true reading or test. Putting a voltmeter in series may show 12.5 volts or higher which is ok but could be misleading in a real-world test. Many times an automotive mechanic will tell someone that "your battery is drawing 12 volts", by putting a voltmeter between the post and wires either on the ground or positive side of the batteries. This is an invalid test using a voltmeter. I won't go into further details to distract from diagnosing the problem at hand. 

I cannot imagine any competent Tech would have simply abandoned a wire without tagging it and wrapping tape around it for safety measures.

The 12-volt test light may or may not glow but if that is the circuit supply power for those fuse panels you can go back there while the test light is in place and see if any voltage shows up. How much is not critical. This is just a test.

You would likely see around 6.5 volts because the test light is a series load and will divide the source voltage approximately in half.

Test lights vary in their "loading" ability. So this voltage can vary.

If you see voltage at the fuse blocks you can compare that to the large red wire with the test light in place. You may need several hands or just use some tape with wire scraps to pull the wires to a safe area for testing.

If you see the voltage at the fuse block you can be comfortable reconnecting it "after' turning off all battery powers and shoreline.

IF that makes you uncomfortable, place a 20 amp fuse in place of the test light. This will provide full power to the circuit and give you more confidence in reconnecting the wire. If the fuse pops, it may be that it is just a bit too small for a test. That is a monster wire and can carry lots of current. I would be comfortable putting a 30 amp fuse in place.

Not knowing specifically how they isolated the Bird System 

 

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Thank you guys, I'll do the continuity test and light test this afternoon.  Stay tuned.  I really do appreciate all this help, I am not knowledgable on this stuff at all.  Lucky for me it was something so obvious.  

And I did hear back from the shop, they did not remove that wire.  They disabled the BIRD by removing one of the little green ground wires off it.  But they also removed the 4th wire from the port, diagram shows that was the inverter wire. That was because we put in a converter.  The inverter no longer sees any AC power going into it.  Then they did something with the 3rd port wire, diagram shows domestic battery switch.  They put in a fast fuse there and a battery charger for the chassis batteries,  All right there.

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This is what the shop just sent me about bypassing the BIRD.

The Bypass went to a DC-DC Converter that protects the lithium from the alternator(and vise versa) and doesn't allow them to burn out the alternator.   This was pulling the 3/4 slots to be able to separate them from the big boy and the interaction with the Chassis battery. 

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  • Tom Cherry changed the title to 2003 Signature PCB 4 & 5 Front Run electrical issues

Based on that picture and seemingly no wire coming in through the second hole from the right bottom power could not get to that far left circuit board.

The wire from that breaker looks to be corroded and I would not leave it that way. Never leave a connection looking like that. Heat build-up alone can make things go bad

If that large wire is what went through that hole then you really don't need to do all the testing I suggested. Looks like a very simple fix. Clean up the wires and tighten them down. 

 

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Thanks Myron.  Plz look at my post above w the diagram of the rr panel.  The above pic only shows ports 1 thru 5.  The port I found the wire hanging out of is port #8. Not in the pic.  And the cb not powered is in the front run panel so I will do your tests

The ports in the pic are #3 & 4 that the shop worked on.  I don't understand it but the cb on the left is powered somehow.  It is the Step, Aquahot and Refer.  Now my Refrigerator has been "hot wired" to the house batteries for a couple years so I don't know if that does anything. My aquahot works and both my Step cover and Door Step work fine.

I'll report back. Thank you!

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OK, all is well.  After totally unpowering the coach and disconnecting the grounds on the house and chassis batteries and shutting off the house and chassis solar, I finally got that terminal dead to insert the big red wire in #8 hole/port.  It appears that what powered that 80A breaker was hot off the chassis batteries and NOT connected to the house disconnect switch as the diagram shows on the pdf I posted above.  So the #4 and #5 PCB boards are now all powered and my stuff is working.  Boy was I lucky that's all it was.

If you guys want to read more, here is what happened when I did the troubleshooting.

Rocketman:  On the top left corner of the pdf doc I posted above, it shows 4 bolts coming into the front run panel.  I tested those yesterday for voltage with the ignition switch on.  The bottom left bolt showed .76 V, bottom right 12.18V and the top ganged bolts showed 3.9mv and 3.5mv respectively.   I ran a 18ga wire, connected to a 22 ga wire to make the 40 feet.  When I ohm tested the big red wire in the back to my 40' wire from the bottom left bolt in the front run box, I got a beep and 0 ohms.  Good to go right?  Maybe not. read on.

Myron:  I measured the wire and lug for voltage.  The wire was dead and the lug/terminal was 12. something Volts.  Next I put the 12 volt test light clip on the lug/terminal and stuck the probe in the big red wire, I got a light.

I checked the voltage on the 4 bolts going in the front run box again.  The voltage swapped from yesterday and I dont know why.  This time the power was on the bottom left bolt and the dead bolt was the bottom right.  Ok this made me mad cause I just checked the continuity on the bottom left bolt!  Oh yeah, the ignition switch was off this time.  I cant remember now if the chassis disconnect sw was on or off.

So the heck with that, we got 3.95 V on the bottom right bolt in the front run box while the test light was in place in the rear run box as instructed.  Don't know why the bottom right bolt and the lug voltage were different.  So we unpowered everything and finally had to physically disconnect the chassis batteries before we could get that lug unpowered.  The pdf diagram was wrong.  I don't know why the voltage swapped from the bottom right bolt to the bottom left bolt in the front run box. And I don't know why the bottom left bolt gave me a good continuity test i think.  We inserted that big red wire in the #8 port and everything works.  Thank you all for your help.  Feel free to comment on the troubleshooting!

 

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No not really, it seems improbable that it could have worked its way out of there but my husband said the Allen screw was loose.  Somebody may have started to remove the wrong wire when doing all that electrical work but they said they didn't have any reason to remove that one. Who knows.

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Glad you safely sorted it out.

When diagnosing complicated issues it is important to have a note pad at hand. Slight changes to procedures or test can have you scratching your head.

The test light in series completed the circuit safely and would have given you the 3-5 volts you measured most likely and since it lit up there was some current flow of course. The test light is a current limiting thing I like to use in many cases. You can connect the gator lead to a source of 12 volts and then touch things that need 12 volts to function and look for changes.

As for the wire coming loose. It could easily have come loose over the years and worked its way out. Seems strange it did not give intermittent issues.

It could have been loose and someone digging around the area could have pulled the wire loose by accident. I am always very careful tugging and pulling "just looking". Installing additional problems while troubleshootiing is a real pain.

As for your strange readings. With that wire disconnected and cycling the ignition switch on versus off there could have been some really strange voltage paths that are nearly impossible to identify. 

I have seen enough power flow though a ground to actually power up a simple device. Those can drive you crazy and that note pad really helps you from losing our mind.

In any case, often fixing the "obvious" first resolves many mysterious problems.

As I recall, there is  a jumper from that breaker to the fuse panel that really needs addressing. It looked like it had some green stuff growing. Never ever let that go. 

Thanks for your patience and giving such great feedback. It makes the journey fun and worth the effort.

 

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