gas gauge

[packerman16]

question on fuel gauge,
64 valiant when I ground tank unit dash gauge works, when I reconnect
dash gauge moves very little. would problem be unit in tank.
thank you

 

[67Dart273]

Grounding the sender wire is just a quick check. It doesn't prove "calibration." But it DOES show in your case that there is certainly a tank / sender problem. I don't know how the sender is grounded on the older cars. Check that out. Sender MUST be grounded. it could have a poor (rusty) connection between sender and tank, and tank may not be grounded.

 

[fistymopar]

The factory had a clip like this, that rots off or needs to be regrounded.
you can add a jumper wire with alligator clip ends from the frame to the hard line coming out of the sender. this should restore the ground, if that's the issue. if not just replace it. Rockauto.com has them for the 70 a body for 58 bucks, should have yours, good luck.

 

[equium]

I ran across this when I had an A100:
http://vintage-vans.forumotion.com/t14006-fuel-gauge-sender-diagnostics
the guy uses a stud gun on the (removed) sending unit to add a better ground.
the post has pictures and is pretty interesting.