Frustrated beyond belief (right rear stop light)

[Blackjack]

I am just about complete with my build and I was testing my wiring the other day and found that something just is not right. But for the life of me, I can not figure it out. Here is my setup and my problem. Hope some of you can chime in and help.

1- my tail lights are LED's with three wires (black, for running light, red, for stop and turn signal, and white for ground)

2 - on my hatch I have the 2 tail lights, and the license plate light.

3 - all of the ground wires for each of the above are connected together, then go to my fuse panel. Then I have a ground wire that goes to my battery, which is grounded to the chassis.

PROBLEM... When testing with the tow vehicle (7 pin connector), all of the running lights operate, the left (yellow wire) side, stop and turn signals operate without any issues. BUT, the right (green wire) side stop and turn signal does not work.

I know what you may be thinking, did he check the tow vehicle 7 pin connection, and the answer is yes. So I know the connector is correct and works. I was testing with a seperate 12V battery for wiring testing because I do not use the on board battery to power my tail lights, just the tow vehicle (which I am sure that is the way it is supposed to be done).

Now, the right side running light operates just fine. I have a 4 pin quick disconnect where my hatch connects to my TD, and when I test the right side there, it all operates just fine. BUT when I check it at where the trailer to tow vehicle wiring is located, I connect a separate battery (for testing) and I get a spark when touching the green wire (right side wire). I have my wiring inside a flexible blue conduit from the front to the rear, so I know there isn't a short there. Plus I have checked all wires to insure there isn't a short and there isn't any.

I am so confused and do not know what to do.

I do not understand HOW I could be getting a short when at the 4 pin connector (at the hatch) there isn't one. I even went out and bought another wiring (4 pin) harness just to be sure that there wasn't anything wrong with the first one I purchased (both sides, male and female sides).

Could by connecting ALL of the grounding wires be causing some type of issue? Somehow, I do not see how that is possible, as there is no voltage on the grounding wires.

This is just so puzzling.

Oh, and to make sure eveyone knows, I have tested each light separately one by one to make sure that each one works independantly, and they do.


HELP!!!

[halfdome, Danny]

Remove the cover off the trailer side 7 pin connector and check if any wire strand is touching.
Being that your getting a spark it makes me think your ground wire has frayed a bit and is shorting out the right brake/turn. Danny

[Shadow Catcher]

Your VOM is your friend, start at the TV plug and work your way back checking continuity and resistance.

[bobhenry]

Returning the grounds to the fuse panel had me scratching my head. I assume you mean there is a grounding lug located on the panel and the grounds are not returning to a fuse.

Have you tried switching the lights or subbing another light for the uncooperative one?

If you cut the light free close to the fixture do you still have a short?
(pinched wire in or very near the light)

remove the ground wire from the un cooperative light temporarly if the short persists 1 of the 2 hot wires is shorted to ground which one is the offending wire the tail or the brake filament?

At this point I would be holding the lamp assembly suspect. I would
Bring the test battery to the now isolated lamp and test by grounding the white and applying 12 volts to the tail and the stop lamps one at a time.

[Blackjack]

LOW AND BEHOLD!!!!!!! After spending what seemed like days, I found that the right tail light's RED stop light wire was rubbing up against the aluminum skin, causing a short. Looks like I did not make the hole large enough, thus when I screwed the flush mounted LED light on, it scrapped the red wire.

Thank you guys for all of your suggestions. I so appreciate it very much. Now the build can continue.......

It's off to finishing the galley!

Robert