gas gauge

[rr41mag]

I just ran out of gas yesterday. My tank reads 3/4 when it's empty. I have a brand new gauge and sending unit. So what do I check first? When I put about 6 gallons of gas in my tank it reads full by the way.

 

[jeffgtoman]

Pull the sender wire off of the gas gauge. With an ohm meter hooked to a good ground, measure the sender wire. Full should be around 10 ohms. Empty should be around 73 ohms. If the readings are not correct, you have a problem with that wire, the sender in the tank, or the ground wire from the sender to the frame.

If those readings are correct, you have a problem with the gauge, the power to the gauge, or the ground to the gauge.

This test basically splits the system in half and gives you an idea of which way you need to go next.

Reading full with 6 gallons and then running out at a reading of 3/4 would usually be caused by a bent float arm. If the float arm is bent down from it's original position, it could cause your problem. There are several ways to get it right. You could pull the tank, pull the sender, measure the tank depth, measure the drop from the top of the sender to the bottom of the float, bend the arm so they match. Don't bend the limit tabs that the sender arm rest on.

 

[savedbyzero]

Do as jeffgtoman suggested. I had to pull my tank put it on the ground and hook up all the wiring and test it. The float arm was binding on the side wall of the tank.

 

[rr41mag]

I've got sidetracked, I gotta gut the interior so I can weld the roll cage in. then I'll get on with the gas gauge