[TBONE1964]

Originally Posted by jjzepplin

So my gauge reads at 1/4 when the tank is full. But on "e" when it is empty. Never lower and never higher.
I guess that would mean that my sender may be of a incorrect ohm scale? Possibly 0-50 or less rather than 0-90?

Someone can correct me if wrong but I believe GM fuel sending units have always been 0- 90 ohm scale from the mid 60's all the way to the 80's

It is possible that it is only reading 0 - 22 (1/4 tank approx) although the float is moving all the way across. The sending unit works somewhat like a dimmer switch on your dash lights. There is a sweep that controls the amount of voltage going to the gauge.


The only real way to test your specific sender is to pull it from the tank and do an ohm sweep test. If it gets to 22 ohms and stops there but you can still move the float from 1/4 to full then I would suspect a bad sender.

If the sender checks out, then I would look at the gauge. It sound like your wiring is OK. The wiring on these are usually on or off and both ways have there own unique symptoms.

Hope this helps.
Tom