Fuel heater on 01

[cathuntmt]

I thought my fuel heater under the filter was not working, so I went to change it and thought I would test one more thing. There is a plug on the back side with two wires one has 12v and the other has 2v. Does anyone know if that 2v side should be 0 or 12??? I was going to try to replace my solenoid but I do not know witch one it is.... Thanks for the help first time poster...