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Its a bad ground, but its easy to fix. By the fuse block/hood open latch (in side the car) there is a bundle of wire, find the light blue wire, cut it and connect each end to the car body. I did mine and it works. But quarter tank is now empty, rpm guage is fine... Hey check out and go to the tech part, and see "dash ground fix" that's how i learned this very helpfull tip.

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โˆ™ 2011-09-13 17:04:44
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Q: Why when I turn on the headlights of my 90 mark 7 the fuel gauge and tach stop working?
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