Third brake light out mystery- 96 Buick Century

Throw a ground to the socket and see what happens.

Hi! All the other lights work great. I get the same 6 volts measuring from contact to contact as I do from hot contact to ground. ???

Hows the connection where the wire harnesses plug together? Clean?

Hi- Yes, and just to make sure I cut it tested voltage there as well, got same 6 volts. I put it back together with wire nuts. I'm still stumped.

Most likely cause of reduced voltage is a poor connection, which causes high resistance. You may need to follow the wire to the front of the car to find the problem area. A wiring diagram and a good understanding of how to diagnose eletrical problems are needed. Electrical problems can be extremely hard OR very easy to fix but you won't know which one it is until you actually find the problem. My advise would be to check the easiest connections you can get to at each end of the wire in question first. If you don't find the problem at either end you will have to follow the wire from one end to the other, which may not be as easy as it sounds.

Did you try to apply a good solid ground to it yet? Bad grounds are the leading cause of bizarre lighting problems in cars. Low voltage like you are seeing is quite common as circuits feed back when grounds are bad.

Hi- I think I'll try that next. I didn't ground it because I was still getting 6 volts when I measured from hot wire to a good ground, as well as from hot wire to ground wire. If that doesn't work I'll try tracing the circuit forward. Thanks!

John

Sorry - did not realize you had measured from the hot lead to a known good ground. Going to another known good ground won't help you much.

Thanks to everyone who chipped in to help solve this- it turned out to be the brake light switch.

John