Fuel gauge, sending unit question

[todtbod]

It's been 20 years since I visited this forum as I built my cobra in 2001. This forum was instrumental in assisting me with my build!

I have a classic instrument hot rod fuel gauge which moves right to left as i drive it and assume it is due to the fuel moving in the gas tank.

I have a M-9407-C50 190 LPH fuel pump which has been discontinued.

I inspected the wires on the gauge and the connections are solid.

I'm thinking that my issue is a sending unit malfunction and the sending unit is part of the fuel pump that is located in the gas tank. Can someone confirm?

Also, is there a way to test the sending unit? If the unit is bad can I replace the unit or do I need to replace the entire pump? If I replace the pump, what are the recommendations?

Thanks in advance for your assistance!

Todd

[Papa]

Typically the sending unit is separate from the fuel pump. Look at the tank and see if you have two locking rings with wire connections to each. Looking from the rear of the car forward, the sending unit would be on the left.

To test the sender, you'll want to remove it from the tank and disconnect the harness. Using an Ohm meter, check the resistance through the full range of motion of the arm the float is attached to. Not knowing what range your gage is expecting, I can't tell you what the proper resistance numbers should be, but that should be easy to find. You are looking for smooth changes in resistance as you move the arm. No jumps or dropouts.

[todtbod]

Thanks Papa! Removed the sending unit and tested it and the change in ohms was not smooth. Ordered a new sending installed it and it is working fine. Thanks again for your assitance.

Todd