Left front turn signal quit working, while right front and both rear signals continue to function properly.
Following the service manual troubleshooting chart and using a volt meter, I determined that the turn signal module was faulty and replaced it. Now the left turn signal works, but both its filaments are dim compared to the right bulb and difficult to see in daylight. Additionally, now the front hazard flashing mode has become a alternating right, left, right, left while the rear lights still flash in unison, as did the front before.
FYI-I found no suspicious looking areas along the length of the light's wires, and relative to the module replacement, I simply unplugged the old unit and plugged in the new. All suggestions appreciated.


Rick in Indiana

 

have you done anything with the run, turn, and or brake lighting system, turn signal switches, front control switch wiring, install a run/turn/brake module and convert the rear turn signals, installed LEDs, replace a bulb before you noticed the left front turn signal failed?

Did the left rear work correctly when the left front was failed?

Are you certain you have the correct module? Did you put the other module back in to see if you still had the original problem?

 

1. I've not done any of the items you've listed. The light simply quit working.


2. Yes, the left rear has continued to work correctly.


3. I assume the module is correct. It is not an after market unit. It is the HD unit ordered though a local shop (not a dealership) that specializes in Harley service work. I did not put the old unit back in and, I believe its on the way to the local landfill.

 

If only one turn signal was not working, it could not have been because of a faulty module...

Both front and rear are on the same circuit, if one is working it means the module is ok.

The problem was in the wiring in the leg going out to the defective signal.

 

Are you sure you replaced the bulb with the correct type?

The front is a dual filament bulb, one for the running lights and one for the turn signal. The turn signal output from the module is paralleled to the front and rear for each side. If the rear is working, then the module is working and the most likely problem is the bulb or wiring.

If you replaced the bulb with the correct type, then it is also possible that it is not in the socket correctly and the contacts are not making good contact or are shorting across the contacts. Take it out and re-position it in the socket.

Last, just because a trusted indy sold you a part does not mean it is the correct part for your bike. I have had so many issues with shoddy bike service and wrong parts that I just do not trust anybody to do a top-notch job except myself. They are in it for their income and all else is beside the point and I am in it for the skin on my *** and their income is beside the point

 

Just found the problem-only due to my daughter's keen-eyed boyfriend. I began looking for a possible bad ground. Working back from the bulb socket with a test wire, it indicated an issue at the stem nut of the side mirror that also secures the turn signal to the clutch lever assembly ( the assembly is new and recently installed). Removing the nut and the mirror stem, I inspected the mounting hole and saw nothing suspicious. However, the boyfriend was convinced there was corrosion inside the hole. So I proceeded to use a rifle bore snake to remove any potential corrosion, which I have to say there was hardly anything to see coming out. Additionally, the mirror stem threads were completely clean. I reassembled everything, after putting dialyactic grease on the portion of the stem that's inside the hole-the light works fine now.


Thanks for your responses


Rick in Indiana

 

Great! Now go ride.

 

Bad grounds will do funny things, glad you found the problem. Hang on to that extra module, they are getting tough to find. YD