ok when I bought my truck it had the trailer light harness that plugs in the factory wire harness. I have used it before when pulling a trailer but never checked the lights because I didnt think they worked on the trailer, well I got one of those harness checkers that you plug in to the truck side to test the wiring. When I looked at it the blinkers worked and the brake lights would light up the right and left blinker leds but not the brake light led and if I had the parking lights or head lights on then no lights seemed to work or they would act weird. I tried plugging the truck connector in to a trailer and the lights acted like the harness tester did. I also noticed my rear licence plate lights were working now. what could it be?

I hope that all made scene.....

 

so you are saying that you installed LED lights in place of the regular bulbs

if you did, you have to place resistors on the wires to cut the voltage down going to the LED bulbs......LED's use roughly 3/4 less power than a standard bulb.....

 

ok I found what the right name for the "harness checker" is, its a trailer wiring circuit tester.

when I say led I am talking about the led on the circuit tester.


I hope this cleared things up a little. I am just not sure how to explain my problem very well.


edit: this is what I used to test the circuit

http://www.autozone.com/selectedZip,.../selectZip.htm

 

no replies.....

Is this because my post is hard to understand or because no body has any answers? I will try to retype my post if need be.

 

bump... sry guys but I need the lights to work

 

hows your ground? make sure you have a good wired ground through your 4way flat plug. grounding through the coupler is not enough.

other then that, i dont know what all to say. if there LED trailer lights they should be made to work on 12V system.

 

I didnt know there was another ground just for that adapter. Ill have to check that.

No the trailer lights are normal trailer lights the lights that are led is the lights on the harness checker.

 

ok, yes you have a 4pin trailer wire. ground, stop/tail, left, right. a ground wire usualy ataches to the chassis on the truck, it goes to the plug and then the plug on the trailer also has a ground wire. its set up as a dedicated ground wire. when the lights have to ground them selfs back thorugh other function wires or the coupler it can cause some goofy stuff to happen to the lights.

 

You have 4 wires. Brown, Green, Yellow, White

Brown: Constant
Green: Right Blinker
Yellow: Left Blinker
White: Ground

(I could have Green and yellow mixed up but I know brown and white are correct)



I sounds like your brown wire is damaged. If you have the stock tow package your WIRES ARE DIFFERENT COLORS. If you did it yourself the colors are more then likely the colors i mentioned above.

You DONT have any lines crossed because if you did all of your lights on your truck would do funny things (I found that out the hard way)

I dont know if that helps you any.

 

ok I fixed the licence plate lights and I checked the harness adapter on the truck with a voltage meter and they all seem to be working right. I think the truck may be wired different then the circuit tester and the the trailer that I connected to, but I wont know until I can find another trailer to try it on because all our other trailers have different connectors and the one I tried before no longer has any lights (its a boat trailer and im restoring the boat and trailer).

After cleaning all the dirt off and looking at the connector on truck I found that it tells what each wire is. On the side that all the truck light wires inter the connector is said something like left blinker,right blinker,parking/tail,brake,backup but no ground and on the side of the connector that you plug in to the trailer is said something like left blinker,right blinker,tail/brake,backup. That is just off the top of my head but I can check later for sure. I do know that it did not have a ground coming in or out.