1. Check the Switch:
* Multi-Function Switch: The problem is *most likely* the wiper/washer switch stalk itself. These switches are notorious for failing and causing this exact issue – they get stuck in the "on" position internally. This is the first place to investigate. Try gently wiggling the stalk while the wipers are running. If you can get them to stop, the switch is almost certainly the culprit.
* Fuse (but unlikely): While a blown fuse *could* stop the wipers, a *shorted* fuse is far less likely to cause them to run continuously. Still, check the wiper motor fuse in the fuse box (consult your owner's manual for its location and rating).
2. Inspect the Wiring:
* Disconnect the Switch: With the ignition OFF, disconnect the electrical connector from the wiper/washer switch. If the wipers stop, the problem is definitively in the switch assembly or its wiring harness.
* Visual Inspection: Carefully examine the wiring harness leading to and from the switch for any signs of damage (frayed wires, shorts, corrosion). Look closely where the wiring might rub against metal components.
3. Relay (Less Likely, but Possible):
* Some wiper systems use a relay. Locate the wiper relay (your owner's manual should help here). If you're comfortable with automotive electrical systems, you can try swapping the relay with a known good one of the same rating to see if it resolves the issue. This is less likely the cause than the switch.
4. Ground Issue (Less Likely): A poor ground connection somewhere in the wiper motor circuit could theoretically cause this problem, but it's less common than the switch failure.
What to Do Next:
* Replace the Switch: If wiggling the switch or disconnecting it stops the wipers, the multi-function switch needs replacement. This is usually the most cost-effective repair. You can find replacement switches online or at auto parts stores. Replacement is relatively straightforward, but you might need to consult a repair manual or online video tutorials depending on your comfort level with automotive repair.
* Professional Help: If you're not comfortable working on your car's electrical system, take it to a mechanic. Diagnosing electrical problems can be tricky, and a professional can quickly pinpoint the problem and make the necessary repairs.
Important Safety Note: Always disconnect the battery's negative terminal before working on any car's electrical system. This prevents accidental shorts and protects you from electrical shock.
