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Hey all. I got my sending unit/fuel pump rebuilt because of the fuel Guage not working. It's always at full. Well, I connected the newly rebuilt pump to the car and moved the float up and down with the key on. No movement of the gauge, and no fuel pump noise..hooked the pump up to a battery and it works. Not so on the car. Any ideas?? Thanks . 1972 vega. Also the fuse for the pump has power

Since neither the fuel pump or the gauge is working it sounds like it could be a bad ground. A bad ground would affect both the pump and gauge operation I believe. Otherwise you may need to track back do the oil pressure switch and see if you are getting any voltage at that point

Similar to what Clyde said: if you were holding the pickup and moving the float you would have to attact a ground wire to the chassis, as the pickup grounds through the tank. The pump operates only when the engine is cranking (gets power from the "S" terminal of the starter) or when the engine has oil pressure, connecting to power through the oil pressure switch.


Chuck

Here is a pic' of the sending unit/pump from a Monza with the ground lug circled. Harry

I'll have to check the ground, and if that's good maybe go to the switch . Thanks for the tips!

I had a similar problem when I installed my rebuilt sending unit. It was a loose wire/bad ground. Easy fix. Good luck!

Rick