Missing Running Lights

[baddog8it]

Working thru some issues on my new/old truck camper. What little I've driven it around, I've limited to day time driving because the running lights don't work. Signals and brakes all work fine.

I've checked all of my wiring up to the point where it enters the camper, and all checks out fine. I've checked with voltage meters and with one of those plug in LED light up thingees at the connection at my truck's bumper.

I don't get a single running light on the camper to turn on. I've checked a couple of bulbs, and they're fine. So, while some bulbs may be burned out, I should at least get some lights lighting up.

I've disassembled, cleaned wire ends and contacts on the camper side socket - so I don't expect a problem there.

Visually inside the camper, I can see very little of the wiring. But inside the cabinet where the incoming socket is, I can see the wire connection to the marker light in that corner of the camper. All looks good and intact, so I see no reason why at least that one shouldn't be working. I can also see some of the wiring at the back of the camper where it enters the back exterior wall (going to the rear lights). No where does any thing look out of place, wrong, or different than I would expect from the original factory wiring.

My next step is to check the bulb in that one marker light (the one immediately above where the socket is). I'm also going to make a new plug that just consists of wire pig tails for each connection. Then I'll manually apply 12V to each circuit, thus eliminating any potential problem with my truck's wiring or the harness between the truck and the camper.

The harness between the truck and the camper is semi factory. I bought a one ended harness and added the plug end that goes to the camper. It checks out as far as getting voltage to the correct pin out.

I have not been able to find a wiring diagram for the camper. I did find a wiring diagram on the internet that appears to match what little of my camper's wiring as I can see. I say that in that the wire color code scheme matches what my camper has. The diagram that I found says it represents typical campers of the 70's.

Any other ideas out there that I'm not thinking of?

Here's my specifics:
1985 Ford F350
1993 Jayco Jay Hunter 950 slide in truck camper.

[BFL13]

Having the same problem with the old camper we just got. I found the problem so maybe same thing with yours.

The positive wire(s) in the camper clearance lights are connected to the tail light wires. The clearance lights get their negatives from the metal skin of the camper.

The lights all need the positives to have 12v and they are in a string so if one has a break in the positive it can stop the others from working. But each light has its own ground from the skin. So if one has no ground the others can still work ok

The ground is by a metal screw with the thread into the skin and the head touching a metal plate by the bulb. Scrape that plate so the screw head has good contact and use a new screw that is not corroded.

If the screw goes into a corroded hole in the skin, move the whole light over a bit so it gets new contact hole with the skin for ground.

On the positive wires, I found part of it would not work and no way to see why inside the skin up there, so I went outside with a new wire from a working light's positive to the positive wire of the string that didn't work and that got 12v to them. So all now work as one string.

OK, what if your skin is not the ground for all the clearance lights, but has individual ground wires? Then I suppose you can do the same thing if there is part that does not work. Run a new wire from a good ground to the neg side of any light that has no ground.

Any by-passing wires on the outside of the camper get covered with white Gorilla tape so it is not so ugly. 🙂

BTW--I blew the 15a fuse in the truck that is marked for "trailer park" a few times until I smartened up and turned the truck lights out while working on the camper lamps. Also the truck lamps turned off by themselves after a time, so I had to keep turning them back on. Lots of going up and down the ladder for your fitness work-out!