C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
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Old Nov 30, 2014 | 03:24 PM
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vette4plus3
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Hey everyone, im wondering if anyone has had the problem im having with my 81, the tachometer and center gauges work fine when u start the car but if u turn on the headlights, open the door, move the ac/heater mode door selector or press the brake pedal all the gauges and gauge lights will shut off, im confused on this 1 since some of those things are electrical and some are vacuum so I have no idea what the cause would be, any ideas???
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Old Nov 30, 2014 | 03:32 PM
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I have a choke light on also if that makes a difference
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Old Nov 30, 2014 | 05:02 PM
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
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You have a ground issue, the common in all the above is the ground.. circuit 150 on the schematic.

I'd check your body ground at the A pillar on the driver side.
I'd check the printed circuit connector where the circuits plug in.
I'd start looking at the headlamp connector next.

The black ground for the headlamp switch is the same circuit as the tach, lighter, dome delay timer, and many other items in the dash. It sounds as if something is seeking a ground.

Willcox
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Old Nov 30, 2014 | 05:27 PM
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that makes sense cause if u play with the headlight switch the lights kinda flicker a little I just didn't think the mode selector for the heat/ac would be tied into any of it, could it be caused by a bad headlight switch and not the ground
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Old Nov 30, 2014 | 06:58 PM
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Yes.. or the connector got hot and melted a tad.. If this is the case and having more info.. I'd pull the center cluster out, and pull the switch to see what is going on.

The page below will show you how to remove the cluster from the car.. then all you have to do is push up on the **** button on the switch, remove the ****, **** retaining nut and switch.

http://willcoxcorvette.com/repairand...lp.php?hID=146 to remove the entire housing..

http://willcoxcorvette.com/repairand...lp.php?hID=263 go to page 7 or so will show you how to remove the switch. If you have any questions feel free to post back.

Willcox

Last edited by Willcox Corvette; Nov 30, 2014 at 07:00 PM.
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