Calling wiring gurus?

[farmall400]

Any wiring guru's here? Or just a wiring diagram.

No brake/signal lights on a 79 C10. Tail lights and reverse lights work fine. No power at the light sockets. Sometimes I have power at the T in the harness (where it T's off to the taillights). Sometimes there is power at the firewall (where the wires go back on the frame) but when there's power there the brake or signal lights won't turn on. I don't have a tester to check the voltage in the circuit.

Is there a switch or common connector that the brakes and signal flashers run through to before current leaves the dash area?

I live on the boondocks, all I have is a test light and an incomplete wiring diagram found on this site.

Thanks!

[farmall400]

Maybe if I reground it.....

[hatzie]

Originally Posted by farmall400

Maybe if I reground it.....

The sheet metal ground behind the left rear lamp assembly is common to all the taillight lamps.

The brake and turn signals are the same filament. The brake lamp feed wire runs from the fuse panel to the pedal switch then up through the steering column to the turn signal switch. The turn signal switch feeds the proper rear filament(s).

Check the wide connector under the column and make sure it's completely plugged in.

If it was just the brake lights I'd look at the pedal switch but the turn signals don't work either... If the plug is connected you may have a bad turn signal switch.

[farmall400]

Thanks for the description, hatzie. I went through that stuff and found continuity. Ground is the the issue...the box sides were just repainted and bolted back on.

[hatzie]

Originally Posted by farmall400

Thanks for the description, hatzie. I went through that stuff and found continuity. Ground is the the issue...the box sides were just repainted and bolted back on.

OK. I've never liked that ground point. I extended mine down to the frame. Did the brake and turn-signals work with the parking lamps off?

[farmall400]

I was thinking of doing the same....extending the ground to the frame.

No brake and signal with the park lamps off, but some of the wires are quite corroded. I'm going to replace all the connections, they're all rusted.