Wiring trouble

[help]

When my tailights are off theres no problems.
When turned on my passenger side brake light stays on. My drvers side turn signal stays on. Then my overdrive kicks off an tranny drops to first gear an will not shift out of first.ive traced all the wiring an didnt find anything wrong. Any help would be great

 

[tacojoel]

Possible bad grounds, or even a short, or open somewhere in the wiring. Could even be rodent damage. Electrical issues can be anything. Would probably help if you let us know what year and trim.

 

[help]

2003 extra cab 4x4 v6. I traced the wiring an found nothing wrong. I pull tailight fuse an everything works ok. Head light switch a possability?

 

[Rock62]

Do you have access to a wiring diagram? You have isolated the problem to the taillight circuit.

I would agree with tacojoel, most probable grounds. The wiring diagram will show where all the grounds are located. Just chasing a wire could easily miss a ground.

Do you have an electrical connector for a trailer? These are frequently suspect, especially if it's an add-on item.

Another possibility is a bulb is burned out or has wonky connections.