Ok I have a 2001 Super Crew that I use to pull my camper. Hooked it up the other day and the left turn signal and break light are not working on the trailer. The trucks work. The parking lights work on the trailer. Just no left break or turn signal. Not the bulb or trailer. Hooked it up to buddies truck and work no problem.
It has no power to the brown wife prior to the female connector on truck. If I trace it up to the connector all is in good shape ???, but if I check the brown wire after the connector still no power. This is driving me nuts !!! I have a trip planned for end of August and need the trailer lights to work...

 

Check your owners manual, page 136.

Power Distribution box ( under hood fuse panel )
Fuse #20 10A Trailer Tow Stop and Left Turn Lamp

Note sure where this part of the post was going :
all is in good shape, does that mean the wire is not damaged, or you have power ?

Start with the fuse under the hood.

 

Sorry SSCULLY, yes the wires are all in good shape with no corrosion. I did check the fuse no. 20 under hood and it's good. Space no. 19 is empty though and has no electrical connector in the slot ? Anyway it all worked back in June but now has decided not to work.
I do understand that a seperate circut runs the trailor lights. Is there anything else I should check ?

 

from personal experiences, i would try putting a new 4 prong on the truck. on my old 02, and my current 04 both of the 4 prongs corroded out and the metal in the prongs just disintegrated into nothing.

 

The correct place. If what you think is slot, 19 is empty, you are not looking at slot 19, that is the stop / turn fuse for the other side, it has to be there else it would not work.

Under the hood, 17, 21, 22, & 24 in that area are not used. You are not confusing 23 & 24 as 19 & 20 are you ?



I assume you are not referring to the passenger cab fuse box, which #19 is an empty slot.

 

One thing to think about while you're in there, go to NAPA and get breakers to replace the fuses. They reset on power down. Only problem I had was the breakers are slightly thicker than the fuses. Had to take my 1/4" wood chisel and trim the plastic back a little. Best thing I ever did with the different trailers I pull.