I have a 94 Buick skylark. The passenger brake light is out but the blinkers and turn signals work fine. I did the usual by replacing the bulb and checking the fuse. The light still doesn’t work. I took the passenger light assembly and connected to the driver side. It worked. So that rules out a bad bulb. Is there a separate fuse for each side for the brake light?

I hooked up a voltmeter to the light assembly and this is what I found. There are 5 wires going to the driver side brake light. 2 yellow 2 brown and 1 black wire. I get 13 volts across the yellow and brown.

On the passenger side there are 2 green 2 brown and 1 black wire. The brown wires go back and connect with the driver side light assembly. The green wire goes back to another connecter next to the trunk hinge. I do not get any voltage across the green and brown wires.

I am going to assume that the yellow and green wires are suppose to be (+) and the brown is (-). If this is true then I am not getting any voltage from the green. Is there a separate fuse for this? Or is there 2 brake light switches on the pedal?

Make sure you have a good ground at the lights and if so then try the following sequence.

First, with the brake pedal held down so that the other side light is on, find out which wire is supplying your power. Take the bulb out of the side that works and check for your power supply that way (you will have power flowing through the proper wires when you connect to the ground through your test light).

Second, now trace the power wires back from the light, checking each connection, to find out when you start to get power. From the point where you have power now trace the wires forward looking for broken wires, crimps etc.