Turn signals work fine; except, when engine is running?

[frioman]

The turn signals on my '85 Am Gen M923 A1 work great until I actually start the engine. After I start the engine and then activate a turn signal, it blinks only once. The turn indicator (light) on the steering column remains constantly lit (not blinking) until I of course manually return the turn signal arm to the "neutral " position.

Please forgive me if this has already been addressed...I couldn't find this specific issue. Thanks in advance for any help you can provide.

 

[dependable]

Sometimes a failing flasher will not work with higher voltage, eg when alt is charging. Would check that first.

 

[bchauvette]

Had the same problem on my M944A1. I took apart the turn signal switch and cleaned the contacts.

 

[frioman]

I disassembled the turn signal switch once already? This time I may spray the assembly with an electrical cleaning fluid. If this doesn't work, I'll likely try the turn signal flasher as "dependable" recommended above. I'll let you know what happens.

 

[frioman]

I didn't replace the flasher unit, but I decided to remove all the turn signal covers and remove, check, and clean the contacts on all on the turn signal bulbs again. BUT...this time I also removed and cleaned the running light bulbs. Now my turn signals are working correctly--even with the engine running.

I don't know if removing and cleaning the running lights solved the problem, or removing and cleaning the turn signal bulbs. But doing one of the two fortunately solve the problem.

 

[frioman]

My last attempt seems to only solve the problem for a short time period. After I remove and clean all the bulb contacts, then start the vehicle, the turn signals initially work. But then it they seem to stop functioning after I turn the lights off, then back on. This is the only pattern I have found so far. I'm about to order that flasher now.

 

[papakb]

I'd suggest that you check to make sure all the wires are properly connected to the composite lights. If you have the ground connected to a bulb the loading changes dramatically and who knows what might happen. You could be drawing current thru 2 bulbs and the flasher might not be able to handle it. Make sure to check the tail lights too.

Kurt

 

[frioman]

Thanks Kurt, I'll check that stuff.

 

[cranetruck]

Sometimes a failing flasher will not work with higher voltage, eg when alt is charging. Would check that first.

I agree.
Always keep a spare flasher around, turn signals are important when on the road.

 

[frioman]

I finally installed a new flasher. That fixed the problem. Good to go now. Thanks everyone for the suggestions.