Running lights work, but only rear turn signal and brake light are out.

[curt777]

So I've been reading a lot about certain electrical issues on 2000 ford rangers, and I've read about the multi function switch going bad, the fuses, the bulbs, bad grounds, loose connections, etc. I've had issues lately with my rear brake light. It was not working when I bought it, and I've been stumped. I've checked all fuses, replaced bulbs twice (bulbs came with truck, and bulbs from oreilys), I know its not the multi fuction switch or the relay near the brake pedal because I have the blinker clicking for both left and right. Right blinks normal speed, and left driver side signal blinks rapidly. All my lights work properly except for the rear driver side, which has two bulbs. The top bulb works perfectly fine, the bottom one not at all. Anyone know where the ground connection for the driverside tail light would be? I've read on a thread here that both taillights have seperate grounds. I'm pretty sure I'm fine to be driving around for now, as its not a major issue, but I would like to figure out why its not working. Any ideas?
Thanks, curt777

 

[lil_Blue_Ford]

So, this is where I really like having a Power Probe (or a knock off) because I can check everything with it quickly. I’ve used a multi-meter and jumper wires before (and sometimes still do) for testing things. Grounds are typically the problem. You need to check things at the taillight that isn’t working, pull the bulbs and test the socket. This is part of the beauty of a power probe, just hit each connection and it tells you if it’s got power, ground, or nothing. It’s a little more complicated with a multimeter, but same thing. Start with the black lead grounded and test the socket on DC volts to find what’s hot and what isn’t. Do an ohms test on the ground wire (black lead still grounded and only touch the ground connection in the socket with the red lead).

This should really be in the electrical forum, so I’ll move it, might get some better responses there.