Debuggin' tail-light circuit

[43687269734F]

Hi, my tail-lights have been on the blink (so to speak), and now that I'm trying to fix that, the circuit has completely died. I suspect a broken wire somewhere in the walls. Any debugging tricks, or will I have to start removing panels and replacing wires? The thing is, when I turn on the lights on the van, the tail-lights on the Airstream no longer work (used to partially) but the van's lights continue to work.

Also, I'm replacing the 7-way connector and outside wiring to the camper. The wires from the camper are Aluminum (fun element) but can I use copper wiring? Wait, that's a dumb question... Cu and Al are not good buddies, is there any way to use both types of metals?

Many thanks

[uwe]

Originally Posted by 43687269734F

Hi, my tail-lights have been on the blink (so to speak), and now that I'm trying to fix that, the circuit has completely died. I suspect a broken wire somewhere in the walls. Any debugging tricks, or will I have to start removing panels and replacing wires? The thing is, when I turn on the lights on the van, the tail-lights on the Airstream no longer work (used to partially) but the van's lights continue to work.

First thing you might do is make sure the taillight housings have a good ground connection. You can check the contacts in the lamp housings one by one to ground with a 12V test light or a volt meter.

Originally Posted by 43687269734F

Also, I'm replacing the 7-way connector and outside wiring to the camper. The wires from the camper are Aluminum (fun element) but can I use copper wiring? Wait, that's a dumb question... Cu and Al are not good buddies, is there any way to use both types of metals?

Many thanks

You might consider an isolated bus bar, and then connecting the wires with good quality electrical connectors to either side of the bus bar. This might help with corrosion issues that would be problematic if you simply twist the wires to gether with wire nuts.

[Shacksman]

Modern trucks will have a fuse for the truck and separate fuse for the trailer lights. Look in your truck manual for fuse locations. My Ford was this way.
Most times the problem is not in the walls. Look at connections or look for an outside mounted breaker on the park light line. I had one on the Argosy just inside the front frame. It rusted and shorted the fuse in the truck that controlled the trailer park lights.

[43687269734F]

Hi all, thanks for the suggestions.

I found some more interesting info. After crawling under my camper again, I "discovered" an access panel by the front tongue. Removing this (with a ton of stuff falling out, thankfully not on my face), I found where the wires go from the trailer connector. All of these are suspect, since most of the electrical tape joining various wires is in really bad shape. And, there's a fair amount of corrosion on these connections.

Anways, this is the first place to clean-up. If the doesn't solve my running lights problem, then I'll do the bulb trick, in case there is a bad bulb. Then if still doesn't work, I get to remove rivets, yippee.

Thanks!

[Mike Lewis]

Originally Posted by 43687269734F

Hi, my tail-lights have been on the blink (so to speak), and now that I'm trying to fix that, the circuit has completely died. I suspect a broken wire somewhere in the walls. Any debugging tricks, or will I have to start removing panels and replacing wires? The thing is, when I turn on the lights on the van, the tail-lights on the Airstream no longer work (used to partially) but the van's lights continue to work.

Also, I'm replacing the 7-way connector and outside wiring to the camper. The wires from the camper are Aluminum (fun element) but can I use copper wiring? Wait, that's a dumb question... Cu and Al are not good buddies, is there any way to use both types of metals?

Many thanks

The place to being your diagnois is at the tow vehicle side of the trailer connector. Of cource you could totally strip the inside of your trailer. That's what we used to call in the auto industry a "SWAG" diagnois. Better know as a "Scientific Wild ASS Guess". Using that approach you will eventually find the problem. However it's much better to us a systomatic diagnois where you start at the source and follow it untill you find the failure.--Pieman

[bhayden]

Originally Posted by 43687269734F

Also, I'm replacing the 7-way connector and outside wiring to the camper. The wires from the camper are Aluminum (fun element) but can I use copper wiring? Wait, that's a dumb question... Cu and Al are not good buddies, is there any way to use both types of metals?

You're sure these are aluminum conductors and not just tinned copper? Aluminum wiring went into some home applications when the price of copper spiked. I think that was in the early 70's. It was a really bad idea and I don't think it's allowed by code anymore. Aluminum wiring gets brittle and cracks (among other problems). If you have aluminum wire replace it where ever possible!

Do you have a Voltmeter (aka Multimeter)? A decent one can be had for ~$30. A cheapie that will get you by for half that. You'll really want to be able to see voltage drops and resistance which the "light bulb" test won't tell you. Analog multimeters are sort of a thing of the past anymore but I still have my old Radio Shack one and there are occasions where it's a better tool than my digital OTC. Anyway, a cheap multimeter is something that's worth leaving in the trailer. You can use it to check AC voltage when you're running off an extension cord or shore power is otherwise suspect.

-Bernie

[GetOutDoors]

Chris,

The wire for tail lights were not ran 'in the wall' in my '66 Safari. They were ran from the hitch to the back of the trailer on the inside of the frame, curb side. Then up through the floor between the tail light and the old breaker panel. If you could get to that point you might see them as they come up through the floor.

If you find this to be so, you could create a few replaceable cut-outs in the belly pan and replace the old wires completely without having to tear the entire coach apart.

The marker lights take off in the wall from there. I found a single run from the curb side tail light to the rear curb marker light. Then another run going to the street side rear marker, then front street marker, terminating at the curb side front marker (they did not go from the curb rear marker light to the front curb marker light because of the door).

Hope this helps.

Calvin