87 Dually Fuel Gauge

[rickyrqacer]

my 87 CC dually sits a long time between uses, it's been 10 months since on the road, although I do start it once a week, yesterday, I started it up and the fuel level arm goes to the 3 o'clock position, the tanks are full, but it's never indicated like that . .. where should I start looking? switching tanks makes no differance ... I need to fix it in the next week, it's racing time ..

Rick

[BLE 'BURBAN]

Check your grounds under the dash and also the ground leads at each tank.

[rickyrqacer]

thanks ble ... I did check grounds, still wierd, everything else works on the dash, any other ideas?

[77shortybawx]

possibly a mouse chewed through the wire that connects the gauge to the sending unit(s).

[BLE 'BURBAN]

Are you sure your selector valve is functioning? The wiring from the sending units to the gauge runs through there as well.
you might also take a multimeter and check the ohms resistance right at the sending units them selves. G.M. fuel tank sending units run the raange of 0 - 90 ohms full to empty. If you know for sure there is fuel in the tank and the sender is in good working order, then with the multimeter grounded good to the frame touch the positive lead to the sender terminal on the top of the tank and check your resistance.