fuel gauge test

[bunchoftrucks]

Does anybody know how to test a fuel gauge ? I have replaced the sended in my daughters 64 ( round speedo, small gauges) so now I have gottenanother speedo set but want to check it before going thru the transplant process .

[William-in-St George]

You can connect 12v to the voltage controler, and ground the sending unit post, gage should peg. Or being very quick!!!!connect 12v to one side of the gage and ground the other. The gage will peg quickly (disconnect the wire as thr gage pegs). If you are swapping a round system for a sweep be sure to ground the cluster to the metal bracket support for the brake pedal. The wiring harness for a sweep verses round cluster is quite different as well.

[R Pope]

If you test it by grounding the sender post, do it very quickly! Just tap the post with the ground wire and watch the needle. You don't want to peg the gauge solidly, it will fry in no time.

[bunchoftrucks]

Thanks guys both guage clusters are the round speedo type. The existing guage just reads a quarter less than it acutually has in the tank. ie. when it shows empty it really has a quarter tank.

[salf100]

The gauge in my 64 does the exact same thing. Havent trouble shot it yet.

[ICEMAN6166]

Thanks guys both guage clusters are the round speedo type. The existing guage just reads a quarter less than it acutually has in the tank. ie. when it shows empty it really has a quarter tank.

a couple of mine do this too, not something i worry about, if it was the other way (ran out at 1/4) then i would remove the sender and bend the float a bit.