1977 weird electrical issues

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Jul 10, 2015 | 08:52 AM

jgcable

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From: Milford, CT

1977 weird electrical issues

On my 77 I have some weird electrical issues. My turn signal indicators work whether the ignition is on or off with the key removed. They are very dim though. If I start the car they work correctly. My heater/AC blower motor doesn't work at all. I did disconnect all the connectors from the windshield wiper motor and I read that they are somehow interconnected? My headlights pop up when I turn my lights on but they don't retract. Lastly... my passenger side window went down but it won't come back up. I can see the draw in the volt meter when I activate the switch and I can see the window make a slight move but it doesn't go up. My car hasn't been "Bubba'd". All the wiring appears to be factory fresh except for the wires that went to the factory radio that were cut when an aftermarket radio was installed 25 years ago.

Jul 10, 2015 | 09:46 AM

doorgunner

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From: New Or-leens Loo-z-anna

Forum members always tell me "Bad Ground" when weird things begin to happen with electrical components.

The problem is to find a diagram that shows where all the vehicle harness' ground wires are located so you can inspect them for looseness or corrosion.

Does anyone have a "ground wire" diagram that they can post or refer us to?

Jul 10, 2015 | 02:48 PM

69Vett

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From: Austin Texas

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it is much less confusing if you post 1 problem at a time.
you will get better results.
turn signal working all the time is incorrect,
you should have 12dvc on the purple wire on the steering column connector,
only when key is on.
lit dimly means something is back feeding(providing voltage when it should not be.)
the purple wire is the supply for turn signals with key on. (should be 0v with key off.
I would verify the Harmonica connector on the steering column is fully engaged correctly with clean contacts. I would also check electrical connections, and rod position adjustment of the ignition switch on top of the column.

Jul 10, 2015 | 04:28 PM

wombvette

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From: New Hill NC

I would check the ground on the blower motor and wipers. They are the same wire and are often hooked up wrong to the starter hot.

Jul 10, 2015 | 06:50 PM

SH-60B

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From: Meriden CT

The headlights not retracting is a vacuum issue, not electrical. Look for any cracks in all the vacuum lines and replace as needed. I think you have power to the window that's stuck down, just the support spring is too weak to assist the window going up. Pretty common problem with a C3.

Jul 10, 2015 | 08:03 PM

jgcable

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From: Milford, CT

Quote:

Originally Posted by wombvette

I would check the ground on the blower motor and wipers. They are the same wire and are often hooked up wrong to the starter hot.

The wiper motor has 2 connectors on it. One is a 3 pin. Lt. Blue, yellow and black. The other is a single pin connector with a black wire. This one has a constant 12v with the ignition on or off.

Jul 10, 2015 | 11:24 PM

wombvette

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From: New Hill NC

Yep, it is hooked up wrong. Follow that black to the starter. Remove it from the hot and put it to ground.

Jul 10, 2015 | 11:41 PM

lowes-yellow77

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Joined: Jul 2009

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From: oak harbor wa

I made this

I made this for someone else having all kinds of weird electrical issues tears ago on a 77 corvette. I have chased and probably know every wire on my car by now, but I wanted everything to work.