Intermittent Turn Signal Issue

[pigdog]

I have the old original style of non-cancelling turn signals. Lately, when I start off, the turn signals aren't working. The indicator light will come on, but doesn't flash.

But after driving for 15 minutes or so, they will work but fail occasionally.

All incandescent bulbs, no LEDs, no modifications made by me. They've worked for almost two years before this started this spring.

Suggestions?

I've pulled the switch apart, found some evidence of sparking (i.e. carbon build up) around one of the contacts, but nothing really stuck out.

Also, where is the actual flasher unit supposed to be mounted? Mine is just wire tied up to some wires. Previous owners...

 

[Mogman]

I have the old original style of non-cancelling turn signals. Lately, when I start off, the turn signals aren't working. The indicator light will come on, but doesn't flash.

But after driving for 15 minutes or so, they will work but fail occasionally.

All incandescent bulbs, no LEDs, no modifications made by me. They've worked for almost two years before this started this spring.

Suggestions?

I've pulled the switch apart, found some evidence of sparking (i.e. carbon build up) around one of the contacts, but nothing really stuck out.

Also, where is the actual flasher unit supposed to be mounted? Mine is just wire tied up to some wires. Previous owners...

I would look at the flasher, sorry I cannot remember where it was mounted..
EDIT, to say I would suspect the flasher.

 

[mgFray]

flasher on mine is on the firewall behind the dash right behind the turn signal arm. Really easy to see without having to take anything apart. Are you having issues with JUST the flasher, or are all your lights going out? Checking grounds might be a good idea, but I agree, I'm inclined to say the flasher module is failing.

 

[pigdog]

flasher on mine is on the firewall behind the dash right behind the turn signal arm. Really easy to see without having to take anything apart. Are you having issues with JUST the flasher, or are all your lights going out? Checking grounds might be a good idea, but I agree, I'm inclined to say the flasher module is failing.

Just the flasher.
Grounds are clean, but haven't done the supplemental harness yet. It's sitting on the work bench.

 

[Action]

When it isnt working, turn on the hazard lights. Walk around your truck and look for the light that isnt on.

 

[INFChief]

Not sure about the HMMWV’s but other vehicle lights needed clean mounting bolts and a good connection to the body as those bolts grounded the lights themselves.

 

[pigdog]

When it isnt working, turn on the hazard lights. Walk around your truck and look for the light that isnt on.

None of them come on when it isn't working, just a steady light at the indicator bulb.

 

[Mogman]

Make sure the wire tagged 57 (k) is grounded, this goes to the flasher terminal C
If that is good you can jump terminal A to terminal B (325 A and 325 B) in the plug (unplugging the flasher of course) and the front and rear lights should burn continuously when the turn signal switch is in position (to say activate right turn and the right turn lights should illuminate)
If they do then the flasher is bad

 

[pigdog]

Make sure the wire tagged 57 (k) is grounded, this goes to the flasher terminal C
If that is good you can jump terminal A to terminal B (325 A and 325 B) in the plug (unplugging the flasher of course) and the front and rear lights should burn continuously when the turn signal switch is in position (to say activate right turn and the right turn lights should illuminate)
If they do then the flasher is bad

Thanks, I'll chase that down this weekend.