Hello, all..


I recently purchased a '71 F100 4X4 with a 360 V8 and 4 spd tranny.
The issue is this.. When I turn the headlights on, the right front running light.. the one in the turn signal and right rear tail light are not lit. However, the turn signal on both still flashes, and the brake light lights up.. just no tail light.. or front running light... the left side seems to be working fine.. also the back up light doesn't work on the right... the previous owner bugged in a license plate light.. which is not working either..could that be the problem???


Any help with this issue would be greatly appriciated....

 

The front and rear lights aren't on the same harness persay, so if there is an electrical issue, it's inside the cab(where they come together). Have you confirmed the bulbs are good?

There are four wires going to the rear of truck:

L turn
R turn
back up
parking light

If one backup light doesn't work either it's: burnout, socket is bad, wiring bad at rear.
The license plate light works off parking lights, so there again, likely a wiring issue out back.

It's typical the sockets get rusty and loose connections. My '70 had problems all the time with the front turn signals not working all the time. Welcome to the rust belt.

 

The parking lamp and taillamp use double filament bulbs (1157 clear or 1157NA amber-parking lamp only).

If one filament burns out, depending which one it is, you could still have T/S, brake lights, but not taillights or parking lamps.