Q: Gas gauge stays at full was fine until I replaced the fuel pump/sending unit

asked by on January 17, 2017

I just replaced my fuel pump with one I pulled from a yard. But now my gas gauge is reading full and doesn't change the sending unit bar isn't jammed I unbolted it and made sure. I tried unplugging the battery also I took my dash apart and physically moved the gauge and it just goes back up. The gauge was working fine. I pulled the pump from the same make model and year as my car the only difference is it had a digital instrument cluster and mine doesn't. I wasn't sure if that made a difference. Napa never asked what instrument cluster I had. I would assume if the new sending unit from the yard was shot it would read empty not full but I'm not sure. Is it possible to take the new pump motor and attach it to the old sending unit with heat shrink? The new pump works but I would like to know how much gas I have as my odometer stopped a few months ago at 78000. I would prefer not to buy yet another pump. Can I easily connect the new pump motor to the old unit that works?

My car has 81000 miles.
My car has an automatic transmission.

Since you took the fuel pump and sender from another vehicle then it most likely needs a new fuel sending unit. The sending unit is most likely corroded from sitting in an empty tank for who knows how long. You should be able to swap the sending units from one unit to the other.

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