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Was wondering if anyone could help me out.  Replaced my gas tank in a 1988 Lincoln Town Car.  Used a sending unit from a 87 Town Car.  Sending unit works but I have no power going to it.  There is a black and yellow wire.  Both seem to be grounded.  Does any one know where the yellow or black wire go to?  All fuses are good.  Don't know where the power comes for the sending unit.  Thanks, :  

The sending unit for the '88 is nothing more than a variable resistor.
The sending unit for the '87 has an extra pin, which is unused.

Black is Ground.

Yellow/White comes from the electronic fuel guage in the instrument panel cluster.