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hbarrineau@hwbeng.net

12 volt mystery

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Have chased down this problem for weeks with no luck. All overhead lights (12 volts) on doorside of 2004 Revolution do not work. Can take jumper cables from ground terminal under bed to ground terminal on light above bathroom sink and everything works so it seems to be a ground wire issue. Have put meter on hot side and get correct voltage. Thought I had this fixed when I ran new ground wire from adjacent fan ground to light fixture ground. All lights and fan worked. I left this for a few days and returned to find it no longer worked. Not opnly did it not work, my luggage compartment switch no longer worked with the appearance of internal arking. Hot side okay but ground side fried.

Local RV dealer not much help. Fleetwood sent me wiring diagrams. They help but they do not tell the entire story.

I consider myself reasonably intelligent (I'm an engineer) but I think this has just about beaten me! :rolleyes:

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I'm no expert but if you have evidence of arcing at a switch, that would be a good place to start. A switch doesn't have a ground side so you are dealing with incoming hot wire and outgoing hot wire to the fixture. If there is grounding in the switch then it would be the cause of the arcing. If you have arcing there should be a blown fuse. Check all your fuses - but find the cause of the arcing or you'll just end up replacing fuses again.

If you put in a jumper to ground part of the circuit and it doesn't solve the problem for the whole problem area then the ground fault must be at a point other than the circuit level. Check at the fuse board to see if the ground wire there is still intact and properly attached.

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Thanks Tom

I check the fuses again. The hot wire at the damaged switch is still hot. The ground wire at the switch is provided only for the indicator light on the switch. I think this is where the related arcing is happening but I'll recheck. I'm thinking the ground fault is at a location other than the circuit level but am having a difficult time following wiring harnesses. Good news is I have it isolated to one side of the coach. No problems whatsoever on the drivers side of the coach. All of the grounds tie to the same terminal strip for both sides of the coach so I'm thinking there's a problem in the doorside harness somewhere. Is there such a thing as putting a signal on each wire in the harness and following it to the fixtures?

Thanks again.

Have chased down this problem for weeks with no luck. All overhead lights (12 volts) on doorside of 2004 Revolution do not work. Can take jumper cables from ground terminal under bed to ground terminal on light above bathroom sink and everything works so it seems to be a ground wire issue. Have put meter on hot side and get correct voltage. Thought I had this fixed when I ran new ground wire from adjacent fan ground to light fixture ground. All lights and fan worked. I left this for a few days and returned to find it no longer worked. Not opnly did it not work, my luggage compartment switch no longer worked with the appearance of internal arking. Hot side okay but ground side fried.

Local RV dealer not much help. Fleetwood sent me wiring diagrams. They help but they do not tell the entire story.

I consider myself reasonably intelligent (I'm an engineer) but I think this has just about beaten me! :rolleyes:

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I don't know about a signal but if you have access to the root of the harness you should be able to do a continuity test for each individual wire while testing for cross connections or shorts. Most inexpensive test meters have a continuity or resistance function or you can make one with a battery, two wires and a light bulb. I would connect one end of the continuity check device to the fixture and then test every wire in the harness to identify any cross connections including the ground to hot continuity. Do this with each bulb in place and without the bulb in the fixture. A slow process but each test gives you more specific information about how the harness is connected.

I think the first step has to be to replace your compartment switch. If there is any arcing or malfunction detected by visual observation as you examine each fixture, replace them. The whole problem could be a fixture malfunction.

I'll bring up one other possibility. In our coach, we have a battery cut-off switch. This switch activates a single Battery Isolator which is a relay that shuts off all 12V electric to our coach. When this fails we have no 12V electric in the coach. I wonder if perhaps you have two of these, one for each side of the coach? If so, perhaps one of them has failed. I am finding that this relay is prone to failure. Our coach is 5 years old and we are on the third one now.

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i have seen these relays go bad also, once i found the problem i put a set of jumper cables across the posts to get the customer home. he had rented the unit and was in town for the race here at bristol. this paticualr relay was going to cost him about 100 bucks, plus more of my time on this unit.

steve sandidge

camping world rv univ

class 54

91 holiday rambler imperial

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