1997 Sierra Tailights?

[supertech1979]

I have a 1997 Sierra, that has had some intermediate problems. Now the problem is that the right back signal/brake lights are not working. I can take it out and plug into the other side and it works fine. It used to do some silly things like, wipers coming on when randomly with signal, signal speed changing fast and slow. My mechanic said when it was doing all that crazy stuff, he thought it was coming from an old alarm system tied into the tailights. He tore it all out and it did better but now it just went out. Inside the cab it blinks like a bulb is out, right side fast, left is fine. I don't think it is the signal relay becuase it's only the one side and not both, not the bulb because it works when plugged into the other. Some guy told me there was a relay, circuit, or some part that goes bad in these that cause this, is that true?, where can I find it?. There was a circuit that went bad for my wipers that I had to replace so its not that far fetched. Any ideas?

 

Nathan

[chevylobo]

change the circuit board on the tail lights. its what the lights plug into mine when i had it did the same thing its like 30 bucks for two. autozone or advanced auto carry them