How to Wire your Car or Truck for Trailer Lights

 

That's a great link there Ray.

 

Tnardo. IF you can only use the brake controller manually than I would check the red wire that comes off of the controller and goes to the brake switch just above the brake pedal. stick a test light on the red wire behind the brake controller and push in the brakes on the truck. IF you don't get anything on your test light there is a connection problem. If your using the factory harness that can be a pain to trace down. If your test light does light up then its more than likely the brake controller itself.


Off the brake controller the wires are as followed for anyone that doesn't know. White=ground, Black=12V power, Red=Stoplight, Blue=output to trailer brakes.

Generally if your having problems with your brake controllers the most common problems are Bad fuse or circuit breaker under the hood. Circuit breakers are generally installed when the vehicle does not have the factory trailer wiring. Just because it has a hitch on it doesn't mean it came with the factory trailer package a common mistake with people.

If your truck has the factory harness it is very seldom it is a wire under the dash more so on the connections coming out of the brake controller to the factory harness.

Another place to check is inside the plug on the truck. Water can get in and corrode the wires. Bad connections can do wonderful things when your trying to tow a trailer.

Also on my 99 I know I had a problem where the main harness comes to the back of the truck. My trailer plug wires go up and plug into the main harness. My trailer brake wire was rotted out inside the plug so i had to by pass the little factory plug run a new wire to the trailer plug

Hope this helps guys

And if your having problems with messing around with test lights find your self a little tester like this. or stop by a local RV shop they should have a tester like this or something similar
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One of the service trucks at work had the wire corrode right inside the factory connector on the back of the trailer plug. Was able to take it apart and reuse the old pin on the wire after I cut and restripped it.

 

Make sure you are getting a good ground when you test. I had a bad wire in mine that I kept chasing. Also, make sure the terminals are clean. I didn't see above if you where getting the trailer lights to work as well. Most of the time the brake controler has to "see" that it is hooked up to work, and I think that the ground connection is how it sees that. If your trailer hookup does not include a ground, then it will ground through the ball. If the ball is rusty or has a fair amount of grease on it it may take some driving to make the connection.

 

Just to update, Ive been away for a week or so, and havent played around with it anymore. I tried the brakes of another trailer and the brakes worked, but I just couldnt get the test light to go on when I was testing. i will try it again, and this time I will hook up the trailer just like i was going to tow it. Last time i didnt, but it still should have worked! Will keep everyone in here updated and thanks to everyone so far for the useful help, and tips and whatnot.

 

If you have two people, you should try to use a multi-meter instead of a test light. I believe the center terminal is ground, and the 2 o'clock terminal is brake. That way you can insure you have good ground, and if you are getting voltage when the brakes are stepped on.

 

the ground is at 5 oclock and brakes are at 7 oclock the center is aux