What relay switch controls the windshield wipers located on a 1998-99 Lincoln town car?

There isn't a single relay specifically dedicated to *only* the windshield wipers in a 1998-99 Lincoln Town Car. The wiper system's operation is controlled by a combination of the wiper motor, the wiper switch (which is itself a complex module often referred to as a "combination switch"), and potentially several relays depending on the specific features (intermittent wipers, etc.). The relays are usually integrated into the underhood fuse/relay panel and aren't directly labeled as "windshield wiper relay".

To find the relevant relay(s), you'll need to:

1. Consult your owner's manual: This is the best place to start. The manual will likely have a diagram of the fuse and relay box showing the location and function of each relay. Look for descriptions relating to "wipers," "washers," or possibly "body control module" as relays often feed power to the BCM which then controls the wipers.

2. Use a wiring diagram: A wiring diagram specific to your 1998-99 Lincoln Town Car will show the exact path of the electrical circuits related to the wipers and the relays involved. You can usually find these diagrams online through automotive repair databases (often subscription-based) or on forums dedicated to Lincoln Town Cars.

3. Inspect the underhood relay box: Carefully examine the relays in the box. Some may have markings indicating their function, but it's unlikely to be explicitly "windshield wiper". You might need to use the owner's manual or a wiring diagram to identify the correct one(s) by testing their continuity with the multimeter. Be careful and only do this if you're experienced with automotive electrical systems.

In short, there's no single "windshield wiper relay" – finding the correct one(s) requires using your owner's manual and potentially a wiring diagram.