last year my gas sending unit went out. i bought a replacement and it worked for the last year w/o incident. was running down the road and ran out of gas when the car said i had quarter of a tank. sure enouph the gauge is stuck at quarter tank.

how do i tell if the problem is the gas guage or the sending unit????

1967 cutlass supreme

 

Get yourself a jumper wire. Attach one end to a GOOD ground. Disconnect the plug for the sender in the trunk. connect the other end of your jumper to the plug (the end going to the gauge). When you turn your ignition on the fuel gauge should go to FULL. If it does then your problem is the sender.

 

I hope it is ok to post here as I have a similar situation. The difference is I am putting in a new sending unit now, as the old gauge always read full; beyond full actually. So I did a dry run with the new unit before putting it in the tank and the needle on the gauge went even further around, but it will not move as I move the arm on the sending unit. I thought I read somewhere about having to recalibrate the gauge, but I do not know how to do this, or if I need to. Thanks in advance for your help.

 

Same problem. Bought a new sending unit from Fusick (0-90 ohm) and new gauge from Autometer (0-90 ohm). On the dry run could not get any reading out of the gauge when moving the sending unit float. Help!

 

I know nothing about re-calibrating the gauge.
I did the above listed test to test my circuit when my gauge read beyond full. The test verified the sender was bad.
Make sure you have a good ground, and make sure the wire from the sender to the gauge is good.

 

My gas gauge is not working either. I looked in my trunk and couldn't find wires that look like they would go to the gas tank. Is it on the top, and will i have to drop the gas tank?

Car is a 1970 Delta 88 Royale Convertible.

 

On my 71 cutlass conv. I had to drop the tank to get to the ground. The other wire came from the trunk. It was brown and in with the rear lights. Mine had a clip that i was able to undo.
Larry

 

The sender needs to be grounded to the body for the gauge to work.

A short alligator clip wire from the sender to the body will ground it, and you can then move the float and have someone watch the gauge.

 

Not sure about a Delta 88, but on my 442 the wires are on top of the tank. the ground connects to the body near the rear axle. The signal wire on mine comes through an opening into the trunk near the latch, then joins the harness going to the instrument panel.