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I have a 72 Mach1.
When I turn on the headlights the gages all go up.
ie. the fuel gage goes from 1/4 to 1/2.
Anyone had this problem?
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This is a total guess but Id check your voltage regulator first.
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I had the same kind of a issue with a truck of mine , found out the circuit board had a bad spot in it, I would turn my lights on and all the gauges would go haywire.
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The headlight also dims the instrument panel lights. Try dimming the lights all the to off and then try turning on the headlights. If the gages do not go haywire you probably need a new headlight switch. Not sure this is your problem, but worth a try.
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Check your body ground and the head and tail light grounds..
Also possible bad instrument voltage regulator.
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Welcome STOY.
Glad to have you with us. It sounds like you have received some very good information and ideas. Check it out and see what you come up with. Let us know the outcome.
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Hi all
Thanks for the thoughts on my problem
I`ll let you know what happens