Originally Posted by willard9
Are there any tests I can do to see what might be causeing the problem?
It blinks fast when the computer thinks a bulb is burned out. Since it comes and goes, it has to be a bad connection. Unfortunately, it can be troubleshot only when it's actually happening.
Something you can do to make it happen is turn on the blinkers, wiggle the wires in the back, and work your way forward, including going to each ground. Have someone watch the rear lights. It will stop blinking immediately if there is a break in the connection, but I think it takes a second or two before the rapid flashing begins.