The 4-Pole Hardwire Kit with Converter, part # 119178KIT is the correct trailer wiring harness for your Mercury Villager. The kit also includes quick splices for tapping into the existing wiring and a circuit tester for verifying your connections.
I have linked you to the install instructions, as well as to an install video that you might find helpful. The video shows the part being installed on a different vehicle, but the procedure would be similar for your Villager, especially the procedure... view full answer...
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