hamm36

Is there a way to check the fuel gage???
Ohms ???
What would be a good Reading ???
Needle is way past the full reading almost to the hot light "idiot light." Sending unit was tested during fuel tank redo, and ground was put back to body.
-72 Supreme-

bigoldscruiser

The resister in the sending unit is approximately 90 ohms but the only way to check that is to have the unit out of the car or be sure the tank is full. As the amount of fuel goes down, the reading will go down as well, the empty position will be near 0 ohms to ground. A full reading such as you describe usually is caused by the wire to the tank being broken or the unit has an open circuit. Disconnect the wire from the tank unit and ground it out. The gauge should read empty.

hamm36

boc, I did check the sending unit when it was out. The ohms varied when I moved the float back and forth.
Is there a way to check the fuel gage cluster ??
The reason I was asking about the gage cluster. While the dash was pulled for repainting the metal in the dash. The fuel gage needle just floated over past full while totally disconnected from everything. I will check by grounding the wire in the trunk that goes to the tank and see if that does anything. I will post results. Thanks.

hamm36

It went to empty, just like you said. I will check sending again. At least I know now the gage is working, that was what I wanted to know. Thanks.

W30post

Then all the wiring from the trunk to the dash is working. You may have slipped the wire off teh sending unit while installing the tank. Ground or sending wire either one slipping off will cause this.

hamm36

I did not state before. After the needle went to empty by grounding it off. I hooked it back up right, and turn the ignition key then the needle goes back to past full. I have tested it from the sending wire to the ground off of the tank. Between the two I get reading in the 11. M ohms and it starts counting up from there. Sending unit is coming back off today.

hamm36

long story short - it is fixed. The lead strap that goes from sending unit mechanism to the bottom of the tank seal plate, was grounding off. I removed the locking washer and put a small piece of thin gasket on top of the rubber that was there, and reattached it. Ohms checked out at 1.6 to 100. I did a test off the back of the car and gage moved to match the float. Reinstalled and put 5 gallons fuel back in. Measure at 1/4 tank. First time in years it has worked.
Thanks, BOC and W30 for your support.