If you have not solved your problem yet trying searching for this part.. LM487
This is what controls your blinkers brakes lights and all. First my driver blinker would work and then not. I thought I had a short since it would come and go but then I was told one day I did not have brake lights. Did a little search and found out about this part. Bought mine from Ebay and it has been working ever since.
Also it is a very easy install