Break lights

[Tractorat]

I thought this was an easy problem, but now its getting to be a pain. I noticed that I had a brake lite out on my TT. I changed the bulbs, found a ground wire on one side that was broken (so I fixed it), cleaned every thing up, etc.



Well, a couple of times while I was trying to figure out what was going on, the brake light that was out changed sides. Then it changed sides again. Anyone have any idea what would cause that ?



Thanks,

TRat

 

[jelag]

You have an overall ground problem in the trailer... . could be at several of the lights, or where the trailer plug connects to the trailer... when you chase lights that change brightness, or come on and go off, its almost always a single ground connection (several wires meet at one spot) or several connections...

 

[Tractorat]

Thanks,
That actually gives me an idea where to look

TRat

 

[Tractorat]

Well,

I dont think its a grounding problem. Everything is steady.



The same wire that lights up the right turn signal (turn signal works great) is the same wire that lites up the stop light (stop lite doesnt work. The pin on the truck side of the hookup lites up when I use the turn signal and/or step on the break.

 

[B.G. Smith]

Having just pulled out the rest of my hair (not many left) because of similar problems on a tilt bed low boy, I tend to agree with Jelag. Is the trailer skin aluminum and are they using the skin for ground? The ground wire in the 7 pin is # 1 terminal and is at 5 oclock position in the truck receptacle and 7 oclock position in the trailer plug. Check for continuity with that terminal in the truck to truck ground and same for trailer to frame ground or skin ground. Let us know what you end up finding. bg.

 

[Tractorat]

Thanks,

Ill check that continuity when I get back home.



But, I do have a question. The left side stop light works. Everything on the left side works. Wouldn't the left side use the same ground as the right side ?

Everything on the right side works but the stop lite.

 

[B.G. Smith]

Yes in the end they all have to ground to the same place. Try something when you get a chance, turn on the clearance lights and have someone apply the brakes in the truck, if the clearance light on the rt. side goes out then it is a ground problem at the rt. trailer light. bg

 

[Tractorat]

Well, I turned on the clearance lights, and they stay on when I step on the brake. BTW, it must have been my imagination when I said first the right stop lite worked, then switched to the left. I was chasing a couple of problems (whick I resolved), and probably just got mixed up.



So, back to the original problem. Left stop lite works, right doesnt. Blinkers and running lites all work fine. The wire that lights up the turn signal is the same one that lights up the stop lite.

 

[B.G. Smith]

Ok, it's possible that the problem could be in your turn signal switch. If you have a volt meter, turn the right turn signal on and check for voltage between terminal #6 in the truck receptacle and terminal #1. #6 is at 9 oclock position and one is at 5 oclock position. If no voltage there and all the fuses and relays for trailer tow system are good then multi function switch is suspect. bg