2001 Trailer Light Problem

My Right Boat trailer light isn't working. During trouble shooting I confirmed that all of the trailer lights are working correctly and that all of the Truck lights are working correctly. I put a new female connector on the truck and using a portable set of lights found that the right brake light still doesn't work. I traced the wiring up into the truck body behind the left tail light and the only way I can get to it is to remove the tail light. I don't want to do this until I've got a pretty good idea of what I need to do to fix the trailer brake light problem. Please remember when answering that both the truck and trailer lights are fully functional and that all of my trailer lights except the right brake light are working correctly when the trailer is connected to the truck.

FLCoyote

 

when you remove the taillight, there will likely be a patch harness of sorts installed between the taillight bulb and the socket on the truck end of the truck's wiring. This is where the signal is intercepted and sent to your trailer, and that is likely where your problem is in a loose connector or broken wire.

So to fix it will likely only require som solder, heat shrink tubing and electrical tape.

Regards,

 

Yes I have had problems with my trailer wiring before - always goes back to the harness for me. I am on harness #2 about to be harness #3 come spring time. Your '01 is likely the same as my '04 in that road grime gets up an opening under the truck which exposes the harness module.

You will have to pull the tailight out (left tailight - driver's side on mine) and depending on your harness style you will see a module (not all are the same as some have wires for brakes on trailers etc.). The intention of the module is to convert the truck wiring to trailer wiring so the correct lights fire at the right time. The module keeps toasting on mine. I replace the module as opposed to opening it up. They are not expensive to replace. They usually come with wiring instructions for installing them but are straight forward once you see all the wires.

Once you open it up you might find that it is a loose or broken wire. Good luck!

 

Thanks for input. I bought a new trailer wiring kit from my local Toyota dealer for $36.40. Everything needed was included. It took me about two hours to install, but thats because I'm not very mechanically inclined and had to follow the directions slowly and accurately. It would have gone faster except the installers of the existing harness didn't follow the directions and I had to figure out what they had done vs what I needed to do. Anyway it all worked out and the problem is solved. The only thing I can figure out is that the problem was internal to the electronic module in the harness.

FLCoyote

 

Right on. Glad to hear you are back in business. I think there are a bunch of diodes in those modules. I don't think it is anything fancy. I will probably open my old one up that I am about to replace for the heck of it...Happly trailerin'!