Backup/reverse light only one on...

[lbrownah]

Somewhat of a cross post, as I posted something similar in the Tow Vehicle forum.

We had a 2007 Denali XL, had to let it go, but able to pick up a 2007 Yukon XL, so very similar vehicles.

Had Argosy for over 3 months now, no electrical issues with the plug into the TV.
In anticipation of a trip this weekend, wanted to go to the trailer and make sure everything was fine with the TV. Apparently the ride high is higher in the Denali, maybe due to the 20" wheels vs 17" currently on this Yukon...whatever it is, have to adjust our hitch.

The bigger issue though lays with the electrical. Had no problem with the Denali and the trailer plug. The "new" TV, an issue. Same TV model (almost) same year, same plug etc. Plug it in and the backup lights turn on dimly on the TV, and, no other lights except the Argosy's back lights are on. Blinkers don't work on the Argosy or do the running lights on the front.

I think I can go under the safe assumption that the issue is with this particular tow vehicle as the previous one had no issue 2 weeks ago.

THe one x-factor here, at least for me, is that the TV's previous owner put in HID headlights. I have an email out to him asking him if he did it or a shop did, but regardless, not knowing enough about HID, anytime there's electrical work done, there's always the chance that wiring was crossed up somewhere, grounds were changed, fuses blown or whatever.

Not being that handy electrically, and not having a testing meter, not sure where to go. Will take it to the GM dealer and hopefully they can fix it tomorrow, but in advance of that, any ideas.

So is it:
A bad TV electrical receiver plug?
Mixed up wires/ground from the electical plug? (possibly modified when TV got HID's?)
A short in the system?
A blown fuse in the TV? Likely not, I assume that electrical plug runs off a single fuse, and since there is a light that comes on (meaning some power is getting to the trailer).

Help..hopefully it is an easy fix. Cutting it close for leaving in a couple days, and if dealer can't take a look at it or figure out what the issue is we have no trailer lights/signals...

Thoughts? An easy GM dealer fix or something a little more terminal?
TIA

[BIGED52]

To me it sounds like mixed up wiring in the TV 7 pin connector. Not uncommon when connecting up to an Airstream for the first time! The GM dealer may not want to mess with it. You may have to take it to an A/S or other RV shop (w/trailer) to have the wires reset in the connector on the TV. Either way check out everything for correct operation before you leave the shop where you get it done. Happy Trails, Ed

[Splitrock]

I've been working on rewiring my trailer plug and I use two tow vehicles. I got tired of messing with jumper test lights and I picked up a 7 way plug LED tester. It's neat as all get out. I just plug it in the TV plug and I can see in a second what's working on the attached LED panel. I shoulda bought this years ago.

Gary

[lbrownah]

Update:

Took it to the dealer, they said everything was good on the TV.

Had the brake controller installed...the took the TV back to the trailer and crossed my fingers.
Good news...they worked for whatever reason.
That is, all except the running lights/clearance lights/license plate light. I know those are all on the same pin (green) on the trailer plug.

Multiple attempts several times this evening haven't been able to solve it.

Tried to replace the fuse for the green wire inside, but didn't help.
So as long as we don't drive at night (not planning to this weekend), well be god.

[ebair]

I had some similar issues recently
Resolved by replacing the Bargman connector on the trailer umbilical
It just wore out, replacement was under $10 and 30 minutes to wire up
The flat blade connectors get squished and dont make contact with the TV
I wiggled the connector and the lights flashed on the trailer,so I changed it out

[lbrownah]

Update #2.

After further review and testing, the plug connectors seem fine in so far as the metal connectors not bent or not touching. Recall that the truck pin connectors also were tested and deemed to be ok.

However, when a 15a fuse for trailer running lights in the truck (#24) was pulled, it was burnt out. Plugging another one in (while the trailer was connected) blew that fuse right away too.

Thus, the problem is in the trailer somewhere. We got some more fuses today for both the truck and the trailer (30a clear cylinder type for the green connector? That's what's in the trailer currently) for the trailer. But we have to test where the issue is...before or after the trailer fuse...then go from there.

So that's the next part of all this, I think I saw somewhere here for a good way to test that.

Still baffles me that our last truck (a 2007 Denali XL) had none of these issues 4 weeks ago and our almost identical new truck (2007 Yukon XL) has them.

[lbrownah]

Edit: Reading another post on the subject, a couple more comments questions:

Is 15a fuse that the trailer running lights are on in the truck enough? The trailer running lights are on a 30a fuse in the trailer.
I had no idea if the previous Denali we had, had as an amp rating for that fuse #.

Someone else mentioned, the license plate light was the culprit for them. I recently replaced a burned out license plate light (that was burnt out since we got the trailer 4 months ago), and, to my recollection, I am not sure if I've had to use the running lights since then (with the previous truck (2007 Denali XL)). Thus, maybe I've had the no running lights ever since that bulb change (I know they did work since we've had the trailer) even with the previous truck and not just the new one.

I don't think I altered anything other then take out the bulb at that time, but who knows.

Anyways, off to the trailer to do some investigating, although I don't have any correct size extra 20a fuses to try that theory with the truck.

[lbrownah]

Not sure why I can't edit my above message.
Anyways, all is solved.
Turns out to be the license plate light. I pulled it, and running lights (and all others still) worked.
Guess I hadn't used the running lights since doing the bulb swap, there was a reason it was out in the first place, and I guess I'll be running without a license plate light until I can fix that...but better then running with no running lights.