Right Rear Taillight

[iamcams]

My right rear taillight is out. The running lights work but the brake and turn signal are out. Swapped connector and bulb and that is not the problem. I took out the bulb and tested the socket using multimeter and when I connect leads I get 12 volts. So in theory everything works. However, light still doesn't work. This means there is a problem when the system is under load right? Where do I go from here?

 

[Curious Hound]

First, there are 2 filaments in that bulb, if the right bulb is installed. One filamunt gets power for parking/running lights. The other gets power for brakes/turn/hazard light. So, one filament could be burned out.

Second, is there a trailer pigtail connected? Often, when people install DIY trailer pigtails, they don't make good connections. This leads to loose or corroded connections that don't work. Look under the rear driver side and examine the wiring connections for problems.

 

[lil_Blue_Ford]

@Curious Hound got it.

I’ll add that I’ve also gotten defective new bulbs before and if everything else checks ok, the ground is usually losing good connection.