[Lifetime Goat]

1971 GTO with fuel gauge not working. Is there a proper way to test the gauge on the bench?

[dataway]

I hooked mine up to a volt/ohm meter and measured the resistance as I swung it through it's arch. Someone will chime in with the spec for it, mine was something like 10-90 ohms I think.

[Peter Serio]

On the reverse of the fuel gauge there are a total of 3 threaded "posts." To bench test you will need some jumper wires + a 12 volt car battery and some fixed 3 watt or higher resistors. On one of the posts you will see a 6-32 nut and a washer which connects that post only to the metal backer. That post to the backer panel is your ground. One of the other posts then gets 12 volt + battery power and the last post goes to a variable resistor (the sender inside of your gas-tank) which ends in ground. And that is how the gauge tells you your fuel level.

On the wire that is the variable to ground (the sender) 1 or zero ohms= E.

44 or 45 ohms = 1/2 scale.

And 89, 90, or 91 ohms = Full.




I will go and take a photo of my test here so you can see how it's done.

[Peter Serio]

In the #1 photo, test wires are: pink wire with the black tracer= 12 volts battery + power. Black wire = ground and the brown wire = variable resistance (the gas-tank sender).


These are 1970 rally gauges; but standard gauges, your 3 test wires would plug onto the posts the same way.

[Lifetime Goat]

Thanks I will take a look this weekend. This has been helpful.

[dataway]

Jeez, sorry, I read gauge, and thought sender.