Trailer Light Problems - Please Help

[rucaradio]

This is a real head scratcher to me...

All the lights work good on the trailer (turn, stop, and parking). One very weird problem tho - whenever the parking lights are on and the breaks are depressed, it kills power to ALL the lights on the trailer. As soon as the break pedal is released, all the lights come back on. If the parking lights are off, the break lights work fine.

I've gone thru and redone ALL the grounds AND positive electrical connections. Could it be a problem in the wiring of the tow vehicle?

Thanks in advance..

 

[ne7800]

Re: Trailer Light Problems - Please Help

get a test light and check all the pins on the truck (or hook up to a buddies trailer) if the truck is fine i would guess there is maybe there is a bare wire on the trailer somewhere if the trailer is more than 10 years old i would consider rewiering it anyway

 

[gleavens]

Re: Trailer Light Problems - Please Help

I agree with the previous post, check the vehicle first, the problem I believe is there. Does this trailer have brakes? The trailer wiring is pretty simple, white= ground, brown = running lights, yellow+ green= left and right, and also power up on stoplite. You can check the trailer wiring with any 12v source and jumper wires following the formula I stated earlier. Note:dont use your test light as a jumper, it won't work that way. Good Luck.

 

[tashasdaddy]

Re: Trailer Light Problems - Please Help

you have a ground problem. very common.

 

[prestonv]

Re: Trailer Light Problems - Please Help

Dont beat yourself up over this. I'm usually the one my buddies call when they have this problem because im electircally certified on vehicles. haha. i have seen pretty much the same problem you are haveing and with the trailers 9 times out of 10 it is a ground issue. you have corrosion somewhere that your electrical parts are grounded or like previously said a chaved wiure touching the frame.. my suggestion is to clean all mateing surfaces and do a very close visual inspection for wires touching grounds. hope you find it
preston

 

[hazwild]

Re: Trailer Light Problems - Please Help

i had the same problem turned out it was the ground eyelet on the port side light that needed to be cleaned.wire brushed it no problems since.

just fyi i have a 2006 karavan trailer

 

[haskindm]

Re: Trailer Light Problems - Please Help

Do you have separate brake light/turn signals on your tow vehicle? If so you will need a converter to operate the single brake lights/turn signals on the trailer. Otherwise, I agree it is a ground problem. Turn the lights on along with your 4-way flashers, you will probably see that the trailer lights go off whenever the flashers come on. Install a separate ground wire from the tow vehicle to the frame (it is probably already in your connector, just make sure it is connected to the trailer frame) otherwise you are relying on the hitch ball to ground the trailer.

 

[Gary H NC]

Re: Trailer Light Problems - Please Help

I agree with all the above....
This is some good info here too....
http://www.etrailer.com/faq_wiring.aspx

 

[chipman]

Re: Trailer Light Problems - Please Help

i had the same problem, mine was a grounding issue, i ran another ground wire to the back lights, and connected it to the trailer in several spots, probably over kill but it worked. my trailer is a 1982 and i think i must have rusted joints and did not connect the ground to the back of the trailer.

problem is with the trailer grounds, most likely not the truck, try trailer first

 

[Splat]

Re: Trailer Light Problems - Please Help

Common. Ground issue

Bill