I am replacing my 1990 Volvo in tank fuel pump and I have gotten the assembly out of the tank. While removing the old pump, I stupidly pulled on the wires and partially unspooled the coiled wire from the little carbon(?) cores inside the insulated housing. What do these things do? Are they essential? Can I just bypass them? BTW, I'm sure that others have mentioned this, but the replacement pump had reversed polarity from the original - thankfully, I tested it and discovered this.

 

Sounds like you may have destroyed the wires for the fuel level sensor. If so your fuel gauge will not work.

 

Thanks, but the wires for the fuel level sensor are separate and involve a potentiometer. These wires are inside a double tube plastic housing that power the pump.

 

you probably have read through this but just in case

In the Tank - 240 Volvo Tank Pump and Sender