1. Check the Wiper Switch:
* The easiest fix: Sometimes, the wiper switch itself gets stuck. Try wiggling the switch back and forth gently while the wipers are running. If they stop, the switch is likely faulty and needs replacing. This is often the culprit.
2. Inspect the Wiring and Connections:
* Look for broken or loose wires: Carefully examine the wiring harness leading to the wiper motor, the switch, and the multi-function switch (if your Jetta has one incorporating the wipers). Look for any fraying, breakage, or corrosion. Pay particular attention to the connections – they might be loose or corroded.
* Disconnect and reconnect: Disconnect the wiring harness connector from the wiper motor. If the wipers stop, you know the problem lies either in the wiring or the switch. Reconnect it and try again.
* Continuity test (advanced): If you have a multimeter, you can test the continuity of the wires to ensure a complete circuit. This requires some electrical knowledge and safety precautions.
3. Examine the Wiper Motor:
* Difficult to test without removing: Testing the wiper motor directly requires removing it, which is a more involved process. However, if the switch and wiring seem fine, the motor itself could be faulty. A faulty internal switch within the motor itself could be causing the continuous operation.
* Visual inspection (easier): Before removing it, carefully inspect the motor for any obvious damage, rust, or signs of water intrusion.
4. Consider the Multi-Function Switch (MFS):
* Common culprit: In many VW's, the wiper function is integrated into the MFS (often controlling lights, turn signals, and wipers). A faulty MFS is a common cause of malfunctioning wipers. This is often more expensive to replace than the wiper motor or switch.
5. Relay (less common but possible):
* Check for a wiper relay: Some vehicles use a relay to control the wiper motor. A faulty relay can also cause this problem. Consult your repair manual to locate the relay if your Jetta uses one. They are relatively inexpensive and easy to replace.
Troubleshooting Steps Summary:
1. Wiggle the wiper switch.
2. Inspect the wiring harness visually.
3. Disconnect and reconnect the wiper motor connector.
4. Inspect the wiper motor for obvious damage.
5. Check the multi-function switch (this is often the culprit).
6. (Advanced) Use a multimeter to check wiring continuity.
7. (If all else fails) Replace the wiper motor.
Important Notes:
* Repair Manual: A repair manual specific to your 1996 Volkswagen Jetta is invaluable. It will show you diagrams of the wiring harness, location of components, and step-by-step instructions for repairs.
* Safety First: Disconnect the negative battery terminal before working on any electrical components.
* Professional Help: If you're not comfortable working with car electrical systems, it's best to take your Jetta to a qualified mechanic.
By systematically checking these components, you should be able to identify and fix the cause of your constantly running wipers. Remember to always prioritize safety!
