Help Diagnosing Brake Light Issue

[Cal2121]

I'm having trouble with my rear driver's side brake light. It doesn't work. I changed the bulb and still no go. I removed the light unit and cleaned the connections, but still am not having any luck. I have a voltmeter, but not really experienced at using it. Is there a way I can test the wiring where I plug the light unit in?

[sargentrs]

If the LH side is working, sounds like a possible grounding issue, bad terminal connection or shorted wire. Hook up your voltmeter, or a simple 12v test light will do, connect the black lead to a good ground, and test each individual socket on the 3 prong plug behind the stop/tail light pigtail. Test the LH side (the one that's working) for a baseline, then check the RH side. You'll have to get somebody to push the brake pedal to test the brake light circuit. If you get a "no power" on any of the sockets, move backward in the harness to the next connection and test again. Keep going until you get source voltage and your problem will be between there and the previous test point. Here's a '70 diagram http://www.fordification.com/tech/wirin ... master.jpg

[Cal2121]

Thank you so much for that helpful information. I will take a look and see what I come up with.

Thanks again.

[cep62]

If you find no power on one side try moving your blinker switch,
the brake light power travels through the blinker switch on its way to the back.