having a bit of trouble

[Kevin71]

I'm having some issues with my 71 F250 //
I have all of my lighting working EXCEPT the left rear brake and turn signal // I have checked the bulbs - sockets - and wiring
all the way to the front of the truck but I can't figure out where to check from there it appears the I have no power anywhere I check. I have traced wiring from the turn switch down to the first plug at the bottom of the steering column and have poke tested the yellow with black stripe wire everywhere I can get to it (yellow/black) seamed to be the one by the diagram. Anyway
not sure where to check anymore I have checked continuity from rear of truck to firewall and seems OK. Any help would be greatly wecomed
THANKS

[Sam I Am]

I'm betting it's the ground at that light housing if neither filament lights.

[rjewkes]

Also i have had the left rear turn/brake wire just die in the plug just outside the firewall in the engine comp before. Sometimes the connectors in the plugs get corroded. maybe take that plug appart and check for power there with the turn signal running. but definitely double check the grounds.

[Thunderfoot]

it appears the I have no power anywhere I check.

Your problem is the Turn Signal Switch (TTS) itself. The rear lights are separated from the front in the TSS so your fronts could work and not the back. This is a common problem that happens when the TSS brakes or the contacts inside it get dirty/broken.

Sometimes just a new TSS cam will fix the problem.

This is what it looks like inside and you can see the separate contacts.

[Kevin71]

Thanks to all for the info // I think I'm leaning towards the TSS now as I have checked the light ground and the
connector plug you spoke of and just pulled the wheel and found connectors on every wire where someone has changed it before
and didn't string the new wires thru the column

AGAIN A BIG THANKS