Why when I turn on the headlights of my 90 mark 7 the fuel gauge and tach stop working?
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 www.lincolnsonline.com and go to the
tech part, and see "dash ground fix" that's how i learned
this very helpfull tip.