69 Rear Tail Light Issue

69 Rear Tail Light Issue. Only one light is blinking. For the left tail light the far right bulb is blinking only and same for the right tail light. What is my issue? Thanks

Step 1: Check the bulbs to see if any are burned out. Then check the contacts on the base of the bulbs to make sure they are good. I have found that if the contacts are dimpled, the bulb is less likely to work properly.

Check other threads here on this subject. It has been covered many times.

here’s the thread. For Step 2 I would check to make sure it’s got a good ground.

https://cccforum.discoursehosting.net/t/67-73-cougar-sequential-turn-signal-trouble-shooting-thread/2419/1