Left turn signal
 

Ok here in lays the problem. I have a 2000 RoadKing and the left turn signal keeps messing up. If I am stopped, the signal works fine. It is when I am riding down the road that it seems to act up the most. When I turn the signal on, like for when I am going to change lanes, it stays on (not blinking). However if when I am riding down the road and I slow down enough to where I am going to make a turn, it will work. I have no problems with the right turn signal what so ever. Any ideas of what the problem is and how to fix it?

Start with the easy stuff first. Check the bulbs front and back. They may appear Ok but the filament is broken.

Yes sir did that and all is well. Still doing the same thing.

your turn signal module has a feature where if you do blow a bulb, it will not flash, so you know there is a problem. If you have a failing ground or a poor connection somewhere in the circuit that is reducing current flow, it can also not flash. It sounds like you're right on the threshold of that current setpoint.
Check your bulbs... if you're running 1156 and 1157 bulbs, this can cause this problem. They do not draw as much current at the oem bulb from harley. Try to find a slightly higher wattage bulb.

Hogdoctor

Ok thanks, I know I put an 1157 in after ther bulb blew. So I will check it and let you know if that did the trick.