1995 gmc right turn signal problems

Don't know about the other person? I'd check voltage and ground for the turn signals. At the rear, the brake and turn use the same bulb filament, just not at the same time. Green is voltage, black is ground. Do the brake lites work ok? You may have a problem with turn signal switch?

I should clarify my problem a little more. When the headlights are off, and I turn on the right blinker, my radio display and gear shift indicator light blink. With the headlights on, the right blinker does not work. The tail lights and brake lights all work ok. Also, with the headlights off and I turn on the right blinker, the left blinker lights (front and back) flash very dim. Any and all help is greatly appreciated.

I'd have to get at the turn signal wiring for the turn switch and check the grounds.

Just wanted to update, the problem was in the trailer plug. Lots of corrosion I guess. I unhooked it, and problem was solved.

good job.