hit brakes, get left turn signal as bonus. hmmm

[Kelbro3]

Before I dive into the wiring, I'll see if any of you have run into this before and maybe save me a few minutes. I've got a 2000 S 4.0 OHV, with 225k on it. About a week ago it started lighting up the left turn signal when I hit the brakes. It lites both front and back and the indicator on the dash. All just burn steady, don't flash, If actual signal is activated it works fine. I do have a trailer harness plugged into the rear wiring and was pulling my trailer when it started, but after removing trailer, the problem is still there. Any Ideas where to start? Thanks.

 

[my pos mounty]

I would start with the trailer harness, more precisely at any splices that were made to it.

 

[Kelbro3]

That was my guess too, it is a aftermarket plug in directly to the wiring harness and has been working well, but there may be a short in there somewhere, I'll pull the plug tomorrow and see how it does without the trailer wire in the Tee. Thanks