GMC Repair: signal and brake light problem, cab 4x4, rear lamp

Question
I have a 1989 GMC 1/2 ton extended cab 4x4 and the passengers side signal light doesnt work in the rear.The front flashes normal until the headlights are turned on and then it flashes fast like there was a burnt out bulb.I tried new bulbs and a tailight board but it didnt help.The tailights and reverse lights work ok.There is no power coming from the connector where it splits off in the back.Drivers side is ok.The brake light on passenger side doesnt work either.

Answer
Did you TEST the NEW light bulb BEFORE you installed it ?.

The rear signal and stop light are the same bulb if memory serves. Back track the wiring harness's GREEN colored wire from within the electrical harness from the tail light to the firewall of the vehicle. You probably have some corrosion at one of the connectors or:

A. You have a FAULTY ground wire (BLACK in color from the rear lamp assembly to the frame of the vehicle.

B. You have a faulty tail lamp housing socket of where the bulb fits into due to corrosion.



Let me know.


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