I'm helping a friend with his home built Fat Boy and his left turn signal is acting strange. It works fine when the bike is at idle but when he revs the engine it stops flashing and goes to steady on like it's brake light. We can't figure it out. I talk to a couple on mechanics and they don't have an answer. Anybody got any ideas.

 

blinker fluid is low

 

Trace the wire from under the seat through the fender and to the blinker. Look for any wear marks on the wire. When he revs the bike it might be vibrating the wire enough if there is a bad spot that it grounds. If his bike is lowered the tire could also have rubbed a bad spot in one of the wires.

 

The wires under the rear fender from the seat to the signal are new and there is no wear. Also we replaced the wires from the signal module to the connector under the seat and the turn signal module. The only thing left is from the switch to the signal module. Someone suggested to replace the bulb...?

 

Just checking but I assume you were having the problem before you started changing everything that you have.