excellant62,
This is my understanding of a flasher unit. It's a bi metal strip that acts as a switch..it is the contact that carries the current for the turn signals. When you indicate a turn, the contacts close. Because they are different materials with different rates of expansion, as they heat up from the current flow they move.
One of them actually moves away from the other and, presto, the circuit opens. It now cools off and again, presto, it closes. What this means is...blink, blink, blink!
If one side of the truck has a bulb that pulls more current than the other side, that side will cause the flasher to do it's thing...real fast. Blinkyblinkyblinky, etc.
Inversely, if a bulb is burned out, no-blinky on that side at all, or a real slow blinky.
I think that's what you have. Maybe it's the trailer light you suspect. This was the $200 version of a 50 cent problem. Good luck.
Stuart
