Gas guage?

[Wicked Wolf Auto]

I just swapped tanks in my 78. The old one looked as if the PO took a sledge hammer to it. Before I swapped tanks the 31 gal. that was in it would only allow me to put approx. 5 gal. in it before the pump would shut off and the gas guage always showed 1/4 a tank. I assumed because of the massive dent it would only hold that and after about 5 gal. of gas my blaze would stop running. But when I pulled the tank it was full and had 20+ gal. in it. The new tank is in and everything works but my guage. I put about 5 gal. in it at first and the guage shot straight to the right and even after filling it it stays there. I bought the tank and sending unit on another board and its a 25 gal. are the guages different between a 25 and a 31 gal. tank?

 

[dremu]

I am thinking that the ground side of the sending unit isn't ... well, isn't grounded. IIRC, the pegging-full on the gauges occurs when the sender is open ... or maybe if it's shorted.

Anyway, methinks electrical issues are afoot, nothing wrong with the sender or gauge per se.

-- A

 

[Wicked Wolf Auto]

I am thinking that the ground side of the sending unit isn't ... well, isn't grounded. IIRC, the pegging-full on the gauges occurs when the sender is open ... or maybe if it's shorted.

Anyway, methinks electrical issues are afoot, nothing wrong with the sender or gauge per se.

-- A

Thats kind of what I was thinking, I thought I soldered it on there good but I guess I'll have to run it dry and drop it again and re do it

 

[alec78]

No difference in the gauge regaurdless of what tank or car in the GM line.

If the gauge is pegged at the 3 o'clock position it means there is an open between the guage and the ground on the tank / sending unit.

 

[elacruze]

just run a jumper wire from the sender mounting plate to battery negative, or to a certain known good ground. That will confirm or eliminate ground faults.

 

[Wicked Wolf Auto]

unfortunatly all these solutions require dropping the tank again.