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Blinker stuck on at high speed

1999 Ford Mustang with left blinker stuck blinking at a high rate of speed with the blinker switch in the off position. when the switch is in left or right function position, everything works as normal. Help???

Normally that fast blinking points to a bad turn signal bulb. Of course, I’ve not heard of designs where it does it in off position - it is normally the case that it would do it when you put the turn signal on. But there is a lot that I don’t know, so I would at least check the turn signal bulbs as a starter. I’d not be surprised if you found one on the left side has burned out.

Thanks I will look into it.

also, if you do find one that went bad, replacing the other one wouldn’t be a bad idea either.

Sounds like a bad turn-signal switch to me. (Part of the multi-function switch.)

Ok, I checked the bulbs. They all work fine. I am looking up the multi-function switch in my Haynes Manual. It’s kind of vague

Yeah, it would not be the bulbs, probably the turn signal switch.

How do I check this? As far as I can tell the switch is working in both turn positions. The hazards work fine as well. The only issue is with the switch in the off position.

Did you figure anything out. I am having a similar problem with a Jimmy and am curios if you solved your problem. My flasher however is clicking in the off position but no lights are coming on. Is your turn signal light actually coming on or is it just clicking?

Most likely either the turn signal switch or the flasher unit. What is supposed to happen (probably) is that the turn signal switch routes the turn signal flasher to either right or left turn signal bulbs – or neither. The speed of the flasher depends on how many bulbs it sees. Slow if they are all working, Faster if some of them are burned out. The flasher should turn off if nothing is connected to it. But either the turn signal is seeing a high resistance connection to ground in its off position, or the flasher isn’t turning off when the turn signal switch disconnects it from the bulbs.

If the turn signal bulbs are actually flashing real fast, the problem is probably the turn signal switch. If all that is happening is the signal clicking noise, I suppose it could be either. Might change my mind about that if I gave the situation more thought.

You DO have the emergency flashers off, right? (I’d guess that you do. You’d notice the dead battery they would probably cause when you couldn’t start the car), If they are on, they are likely to interact with the turn signals in weird and wonderful ways.