gas gauge!
 

88 chev 3/4 ton, gas gauge shows full, all the time. Every now and then it drops to empty but then jumps back to full again. I have to do a fuel pump soon so I want to diagnose this and fix it at the same time

sending unit

Where is that located?

it's all one peice with the fuel pump. Replacing the pump will fix your problem

Thanks a lot

I have the fuel pump and tank etc apart and what I think the sending unit is looks pretty screwed, and a new one didn't come with the new pump...

You can buy the pumps separately or the whole assembly. Sending unit is about as complicated as a toilet tank float. Float and a resistor. I'll bet the float is not moving freely. Gummed up.

it is probebly gummed up and stuff or there may be a ground wire loose or soemthing ground wire can cause the same effect

the baffle in my tank wasnt mounted anymore, it must have smashed off the sending unit because I found it in the tank. replaced tank and fuel pump assy, ran good. thanks guys