Why would the windshield wipers only work when right turn signal is on a Mercury Villager?

There is no electrical connection between the right turn signal and the windshield wipers on a Mercury Villager. If the wipers only work when the right turn signal is on, it is likely a wiring issue.

Here are a few things you can check:

* Check the fuse box for a blown fuse. The fuse for the wipers should be labeled "Wipers" or something similar.

* Check the wiper motor relay. The relay is located in the engine bay, and it is usually black or gray.

* Check the wiring harness that connects the wiper motor to the fuse box and turn signal switch. Make sure the wires are not damaged or disconnected.

If you are not comfortable checking these things yourself, you can take your Villager to a mechanic for diagnosis and repair.