gas gauge again

[joe hermanek]

all right I took the sending unit out of the tank leaving the orange wire connected to unit then I grounded the unit with my test light & moved the arm up & down ,now the gauge responds but only to about 1/2 full & the needle moves very slowly to the 1/2 fill mark,also I noticed when I would move the arm the test lite would flicker while doing so , should that do that beings the test lite is the ground ? thanks again

[Montana71-F100]

The inside of the sending unit has a rheostat. As the arm goes up and down, it makes contact on different parts of the rheostat. There may be wear in the rheostat or oxidation. I took mine apart and used steel wool to clean the rheostat. I used a multimeter meter and hooked it up to the sending unit so the needle of the multimeter worked as the gas gauge so I could tell if there where any dead spots. It wasn't hard to take it apart. Its held by tabs which are easy to bend with a pair of needle nose pliers.

The reason I took mine apart was to get the gauge to read "Full". There is a stop on it to limit the travel of the arm on the rheostat. I bent the stop so it would travel farther. As it turns out, that may not have been necessary. The problem was in the instrument panel voltage regulator. I adjusted it to give more voltage.

[basketcase0302]

http://www.fordification.com/tech/fuel- ... -units.htm