1989 Ford F-150 Fuel Guage problems - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

smokeybones · 11-06-2011, 04:06

I have a 1989 F-150 XLT Lariat 4x4 and my gas gauge won't work. If I turn the ignition switch off and press the brake pedal, it runs the gauge all the way up until pegged; but when I turn the switch back on, it runs it back down to empty. Does anyone know what the problem could be?

**R.S.LOGAN** · 11-06-2011, 04:41

Check earths / grounds and wiring at tank unit .If not that test tank unit .

smokeybones · 11-06-2011, 08:52

tank unit was good when I tested it. I couldnt find anywhere that the brake wires and fuel pump assembly wires were in close proximity. Do you think it could be behind the dash or under the hood?

**Bert** · 11-06-2011, 09:10

What does the gauge do if you don't step on the brake right after you turn the key off? Can you step on the brake anytime the key is off and have that happen?

smokeybones · 11-10-2011, 17:26

yes, any time i step on the brake pedal when the switch is off it still causes the gauge to go up.

**Bert** · 11-10-2011, 19:21

When you use the turn signals do the arrow indicators light up? How about the hazards. When did this start?

**R.S.LOGAN** · 11-11-2011, 03:01

No earths / grounds on dash wiring ?

smokeybones · 11-17-2011, 07:38

the truck was like this when i got it. the guy said he put a new radio in it and the gauge stopped working.

**R.S.LOGAN** · 11-17-2011, 08:21

Pull the radio out and see how he wired it up , May have taken an existing and used earth / ground for set , wont know till you check .