fuel gage doesnt show full

[caprisecca]

I have only ran two tanks through my new 90 festiva and the gage only goes up to 3/4 full. both times. both times I filled it when it was on empty and both times it only took around 6 gallons. I have tried using the search but didn't come up with much. any ideas?

[bravekozak]

You either have broken resistance wire inside your sender, your float arm is incorrectly bent or your fuel level sensor is not responding properly to the correct amperage. The shop manual says that a possible cause could be due to a defective instrument voltage regulator.

FULL 7 ohms (low resistance)
1/2 32.5 ohms
EMPTY 95 ohms (high resistance)

The fuel tank capacity on a Ford Festiva is 10 U.S. gallons.