gas gauge wiring

[blazeonchevy]

so ive been driving my blazer around with no gauge for a while and im getting tired of it. so does anyone have some sort of diagram for all the wiring involved or advice?. has two wires coming from the sending unit. one goes to ground and the other goes up the framerail. so should this wire have power when the key is on? where does this wire go to. its on the opposite side of all the gauges and i cant figure out where it goes. and i suppose the sending unit or the gauge could be bad but i want to see what the wires are doing first because i have had similar problems. and this is on a 78. any advice is appreciated. thanks

-sam-

 

[mouse]

That other wire goes directly to the gauge...it senses the resistance of the in-tank potentiometer. If you want to test that take a resistance reading of the float. It should read between 0-100 ohms IIRC.

 

[readymix]

0 - 90 Ohms

 

[garlicbreath]

So is the resistance reading from ground to sending wire?
I have a 71 and am doing the same thing. 2 wires to guage.