Hi I recelenty replaced the fuel pump and sending unit to get my fuel gauge to work again and it did not work i would like to know if i have to fill up the tank to get it to read again it still reads full or is there a way to reset the computer to get it to work again It is a 1991 Chevy k2500 4wd 5.7l v8

Thank You
Michael

 

How to Check a Fuel Sending Unit | eHow.com

Test it first, then make sure you install it with room to move around. If the sending unit is restricted in any way it will give off inaccurate readings.

 

It should work without filling the tank up all the way. I would also check the wiring to the fuel pump. Might be a short that is causing you to get the full reading.

 

double check plug ends are not dirty and are clicked in tight

 

I am pretty sure this works off a 5 volt signal to a variable resistor (sending unit), reads the value to the guage (module) from a ground. If the resistor is "open" equates to full, then it lets the full five volts back to indicate so. If the tank is 1/2 it grounds 2.5 volts, the other 2.5 volts goes to module, and equates to 1/2 tank ect. I'd clean the connectors with non conductive contact cleaner. Was this doing the same thing before? If so, one of those connections ( I don't have a schematic to tell you which) with an ohmeter should read to ground. It could be a bad wire from the connector to ground.