There is no new wiring harness needed.
You need to get access to the FDM at top of the tank. You can get to it by dropping the tank or taking the bed off.
You will need the fuel line disconnect tools and two vice grips to tap the ring around on top of the FDM to take the ring off.
Each FDM will cost about $150.00.

Cut and crimp on the wires of the new one:

The tools you will need:




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