FUEL GAUGE NOT WORKING CORRECTLY

[john saleeby]

87 GN fuel gauge needle is barely visible on the full side of the gauge.
What is a decent aftermarket fuel sending unit? Gonna buy one and test to see whether it's the sending unit or the gauge itself. I'll keep the new sending unit on hand if it turns out to be the gauge.

Thanks in advance.

 

[Lil Truck]

The method I use to check the gauge on many types of cars is to unplug the sending unit wire at the tank.
I use a 0-300 ohm potentiometer, one side connected to a good ground source and the other to the wire going to the gauge. Turn the ignition to on position the turn the potentiometer fully one direction. If the needle on the gauge doesn’t move the potentiometer is most likely at 0 ohms, if the needle is max full back it down until the needle just starts to move from full. Now with and ohm meter read the resistance across the potentiometer leads. Most standard gm gauges are 0-90 ohms. 90 full and 0 empty, If the needle does not move the gauge may be bad or a bad wire connection to the gauge.

When installing a sending unit in the tank make sure the float rod moves freely full sweep and the baffles in the tank are secure and not interfering with the float movement. I always test the sending unit resistance before and after it is installed.

Quality sucks on nearly everything today so I don’t have a brand to recommend…..

 

[john saleeby]

Thank you Lil Truck. I'll put that test procedure to good use. Great seeing you at Bates.