71 electrical mystery

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Mar 19, 2002 | 09:30 AM

keytech

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Racer

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From: Atlanta, GA USA

71 electrical mystery

Yesterday my power windows quit working, fuses ok. At the same time my lights would dim for just a second in about ten second intervals. This only occurs when the engine is running. I also hear a dull click sound at each dim interval. The sound seems to be coming from behind the dash on the drivers side. When I'm outside the car and put my ear to the wiper grill I hear the clicking (almost like the sound of a slow turn signal), inside when I stick my head under the dash you can hear it but not quite as loud.

Any clues on this little mystery?

Mar 19, 2002 | 10:40 AM

Smokehouse69

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Re: 71 electrical mystery (keytech)

I don't have a electrical schematic with me, but it sounds like a relay is clicking over. I think the relay associated with the electric windows is underneath the console right under the ashtray area. It might be what you are hearing clicking.
Check your window circuitry and see if it is in good shape. Luckily for you the window harness and circuitry are one of the easiest on the car to trouble shoot. There really isn't a whole lot to it.

Mar 19, 2002 | 11:09 AM

keytech

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Re: 71 electrical mystery (Smokehouse69)

Thanks, I'll check that out. Need to get in there anyway, crossed my fiber optics for the turn signals last time I was in there.

Mar 19, 2002 | 02:00 PM

Easy Mike

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Re: 71 electrical mystery (keytech)

Turn signal flasher is behind the right (passenger's) dash pad. I suspect that is the source of your clicking sound. Are your power windows working? Does your stereo work? The window relay is ganged with the stereo. Check the fuse for the stereo.
:)

[Modified by Easy Mike, 12:02 PM 3/19/2002]

Mar 20, 2002 | 12:14 AM

keytech

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Re: 71 electrical mystery (Easy Mike)

The power windows aren't working. The headlights will dim down (almost off) for just a blink about every ten seconds. The radio and internal lights (if on) also blink right along with the headlights.The clinking sound seems to come from behind the driver dash or just inside the engine compartment. Strange thing is it doesn;t do it with the engine off and just ignition or accessory on. Darnedest thing.

Mar 20, 2002 | 01:00 AM

Smokehouse69

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Re: 71 electrical mystery (keytech)

Have you made any progress finding it? I'm interested, I have been trying to keep track of all the different electrical problems on C-3s, I'm sure that I'll probably suffer from all of them before I get my car finished.

Mar 20, 2002 | 01:27 AM

WATTAC

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Re: 71 electrical mystery (keytech)

Your power windows are shorted somewhere. The clicking you're hearing is the circuit breaker mounted on the firewall somewhere around the wiper motor. The AIM diagrams aren't too clear. Don't allow this to continue or you're likely to ruin the breaker, or worse yet start an fire. The breaker is a "thermal" device that opens when it gets too hot, then cools and closes for a second try. If the short remains the breaker will just continue to cycle until it breaks. The main power for the power windows comes from a connection at the horn relay. You need to locate this wire and disconnect it until you can find the problem with the windows motors/switches/wiring.

Andy

Mar 20, 2002 | 08:19 AM

keytech

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From: Atlanta, GA USA

Re: 71 electrical mystery (WATTAC)

Great answer! That's exactly where the sound is coming from and sounds exactly like what you describe. I'll leave it sit till Saturday when I have time to get to it. Thanks! Let you know how it goes. This happened right after I went to the post office and picked up a big package. The box filled the passenger side and then some. I wonder if it wasn't laying up against one of my window switches forcing it the whole ride, or maybe just a coincidence. (guess I'll use the luggage rack next time)