kshots

Not sure what to think of this... when activated for more than 30 seconds (not consistently, sometimes several minutes, sometimes as short as 30 seconds), both my turn signals stop cycling. When deactivated and reactivated, they work fine for another 30 seconds or so. I'd know where to look if the problem were not intermittent, but I'm scratching my head on where to start if it is intermittent.

Scouring the interweb, the MFS (Multi Function Switch) is a possible candidate... but the symptoms don't quite match. If the MFS was bad, it would not work at all. Same if the flasher was dead. If a bulb was out, I'd get rapid clicking on the signal with the bad bulb. I've no idea where to look if it's intermittent . Any ideas on how to diagnose the problem?

Urambo Tauro

Yeah, intermittent problems suck. It could be the MFS, but if you can catch it in the act, try testing for power and ground at the flasher first. What year is the car?

kshots

It's a 2004 3.9L coupe

Urambo Tauro

Okay I think some of your wire colors are going to be different than mine then, so I'll tread carefully here. Have you tried activating the hazard lamps to see if they're affected too?

kshots

Not yet, I'll try it next time I climb in.

So, the idea in your first post, if the flasher gets power cut off (or loses it's control signal) when the signal dies, the problem is before that component? Makes sense to me, that should help narrow it down. I should be able to either trace it to the flasher or eliminate it as a possibility.

kshots

I'm starting to lean towards the MFS as the culprit. The hazard lights are unaffected - during the dead period (left the turn signal on until it stopped), I turned on the hazards and they turned on immediately. It also seems susceptible to movement - I noticed it restarted as I moved the signal back to the home position, and once it resumed on its own as I continued driving. It's the perception that it may be susceptible to movement that's convincing me it's the MFS.

Urambo Tauro

Yeah, that could very well be it, then.

You did mention, though, that cancelling and re-activating the turn signal would get it working again for another 30 seconds or so. Any chance that switching to hazard lamps triggered a similar "reset"? Did you run them long enough to feel confident about the problem being limited to the turn signal function?

kshots

Ok, I have an update...

1. The replacement MFS that CJ sells as a "direct replacement" is not... the original is a 4-way (up, down, forward, backward) switch, the CJ part is only up, down, backward (no forward).

2. The CJ switch does not activate my brights (original did)

3. The MFS replacement... did not resolve the problem. I thought it did for a while, left my signal on for several minutes after replacement... but the next day it was back to intermittent.

Odd thing is I can keep the hazards on indefinitely - they flash without fail on both MFSs. With that being the case, I'm not sure I can see the problem being the flasher unit :/... I'm out of ideas