My truck is a 65 the directionals work but no brake or tail lights. Also when brake is applied tails keep blinking. I have found some good tips on the GMC site but just wondering is there any common thing that would cause this problem before I start testing everything. This being Mothers day weekend I will not get in much garage time in so just planning on the best way to attack this. I guess it could be a combination of the headlight and directional switch.
One more thing the 3 wire connector I have read about on the fire wall going to the rear lights I am correct in thinking that I can just pull this connector apart at the firewall(inside)
Ed