LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 2000 >> Grand Cherokee Laredo, 4.0 S, AWD >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Modules >> System Tests >> Windshield Wiper/Washer System >> Wiper Operates Constantly With Ignition On
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Wiper Operates Constantly With Ignition On

  1. Replace wiper on/off relay in Power Distribution Center (PDC) with a known-good relay. See Figure. If wipers do not operate, go to next step. If wipers operate correctly, replace wiper on/off relay. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  2. Turn ignition off. Remove wiper high/low relay and on/off relays from PDC. Using DVOM, measure voltage between ground and wiper high/low relay socket terminal No. 30 (Yellow/Dark Green wire). See Figure. If voltage is less than 10 volts, go to next step. If voltage is greater than 10 volts, repair short to voltage in Yellow/Dark Green wire. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  3. Disconnect wiper motor connector. Turn ignition on. Using DVOM, measure voltage between ground and wiper high/low relay socket terminal No. 87 (Red/Yellow wire). If voltage is less than 10 volts, go to next step. If voltage is greater than 10 volts, repair short to voltage in Red/Yellow wire. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  4. Using DVOM, measure voltage between ground and wiper high/low relay socket terminal No. 87A (Brown/White wire). If voltage is less than 10 volts, go to next step. If voltage is greater than 10 volts, repair short to voltage in Brown/White wire. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  5. Using DVOM, measure resistance between ground and wiper on/off relay socket terminal No. 85 (Black wire). If resistance is 5 ohms or greater, go to next step. If resistance is less than 5 ohms, repair short to ground in Black wire. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  6. Turn ignition off. Connect test light between wiper on/off relay socket terminals No. 85 and 86. Turn ignition on. Using scan tool, actuate wiper relay. If test light pulses, test is complete. If test light does not pulse, replace Body Control Module (BCM). See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
scientia non olet · About LEMON Manuals