blackhawkkid308

i just bought a 92 lx convertible and the only thing doesn't work is the fuel gauge. i have grounded all the wires in the 4 wire plug that operates the fuel pump. the only one that shows power is the fule pump wire. it goes bright red on a test light while the relay is ingauged and then goes dim until the oil pressure switch turns it back on. where the heck do i go next in trying to fix my problem. i even called ford dealer and the tech said to ground across the 2 smaller wires that they operate the gauge and sender. gauge stays on empty.
HELP!!!
bhk308

blackhawkkid308

i pulled the dash today and when i unplugged the small green circuit board the fuel gauge went to above full, does this mean the circuit board is bad or the sending unit?

mattdel

The fuel level sender is a different unit than the fuel pump, unlike more modern cars where it's all one assembly. The wire color you need to ground out is Yellow/White.

You can also check the continuity between the two terminals of the sender. Full tank will have 145 ohms, Empty tank will have 22.5 ohms.

blackhawkkid308

it was the green circuit board that plugs into the back of the instrument cluster called the instrument cluster voltage regulator.
bhk308