Help - trailer wiring

[Fazerfish]

This summer I bought a 2000 Toyota 4runner to pull my boat around. First thing I pulled was a company trailer and noticed that the left turn signal didn't work, but the break lights did. No biggie, at least I had break lights.

So when I went to pull my new boat, the same problem. I got out the volt meter and determined that no signal was getting to the wire at the plug of my SUV. Break light signal and right turn/tail signal worked, just not left turn/tail signal.

I checked the fuses and they are all fine. The wiring goes up into the frame and disappears. No idea where it comes out.....

Anybody have this problem before or know what I need to do next?

[Jeremy airjer W]

If its a factory harness start unplugging all the connectors and checking for corrosion. If its an after market harness than find the converter box (Toyota uses a separate turn signal and break light which requires a converter to correctly supply either the brake or turn signal to the trailer), check for the turn signal power going into the converter. If theres power going in and nothing coming out than the converter is bad. Converters are not uncommon to go bad. Northern sells just a basic converter kit for under $20.

[Fazerfish]

I took it to a Toyota dealer just to see if there was a separate fuse box I wasn't checking (everyone kept saying it was a fuse) and he took one look at it and said it was an after-market. I don't know how it could be, the wiring goes up on the frame in the back and disappears. Not sure how someone would wire this without doing it at the beginning.

Would this converter be up toward the engine or back before the wiring disappears in the frame?

[Jeremy airjer W]

Its after market, it could be anywhere! I like to mount them behind the taillight assemblies whenever possibly. You'll need to follow the wires as best you can to see where they end up. Its very possibly that its above your feet as all the connection that need to be made are in that location. The box also stays out of the elements as well.

[Fazerfish]

I'll look around some more and see if I can find it.

Thanks