Intermittent Wipers Inoperative Or Erratic

Possible Causes:

1. Fused B+ Circuit
2. Wiper Mode Switch Sense Of Multifunction Switch
3. Intermittent Wiper Switch MUX Output Of Multifunction Switch
4. Wiper Switch Mode Sense Circuit
5. Intermittent Wiper Switch MUX Circuit
6. Central Timer Module
7. Wiper Relay Control Circuit
8. Wiper Relay Output Circuit
9. Multifunction Switch Low Speed Output
10. Low Speed Wiper Switch Output Circuit
11. Wiper Relay

Testing

1. Turn ignition off. Remove wiper relay, located behind glove box. Turn ignition on. Measure voltage between ground and wiper relay harness connector terminals No. 2 and 5 (both Dark Blue wires). See Figure . If battery voltage is present both circuits, leave wiper relay removed and go to next step. If battery voltage is not present, repair open in appropriate Dark Blue wire.
2. Turn ignition off. Disconnect wiper motor connector. Turn ignition on. Turn multifunction switch to inoperative intermittent position. Using a DVOM, measure resistance of Black/Tan wire between wiper motor connector terminal No. 15 and wiper relay connector terminal No. 3. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, go to step  10 .
3. Connect a test light between wiper relay connector terminals No. 2 (Dark Blue wire) and No. 1 (Dark Green/White wire). If test light does not turn on and off, go to next step. If test light turns on and off, replace wiper relay.
4. Reconnect wiper relay and wiper motor. Using a DVOM, backprobe between ground and multifunction switch connector terminal No. 4 (Violet wire). If battery voltage is present, go to next step. If battery voltage is not present, replace windshield wiper multifunction switch. See MULTIFUNCTION SWITCH  under REMOVAL & INSTALLATION.
5. Backprobe between ground and multifunction switch connector terminal No. 2 (White/Brown wire). If voltage is more than 2 volts, go to next step. If voltage is less than 2 volts, replace multifunction switch.
6. Backprobe between ground and Central Timer Module (CTM) connector C1 terminal No. 3 (Violet wire). See Figure . If battery voltage is present, go to next step. If battery voltage is not present, repair open in Violet wire.
7. Backprobe between ground and CTM connector C1 terminal No. 12 (White/Brown wire). If voltage is more than 2 volts, go to next step. If voltage is less than 2 volts, repair open in White/Brown wire.
8. Using a test light connected to ground, backprobe wiper relay control circuit at CTM connector C1 terminal No. 4 (Dark Green/White wire). If test light blinks, go to next step. If test light does not blink, replace CTM.
9. Using a test light connected to 12 volts, backprobe at wiper relay connector terminal No. 1 (Dark Green/White wire). If test light blinks test is complete. If test light does not blink, repair open in Dark Green/White wire.
10. Remove wiper relay. Connect a jumper wire between wiper relay connector terminal No. 3 (Black/Tan wire) and ground. See Figure . Using a DVOM, measure resistance between multifunction switch connector terminal No. 15 (Black/Tan wire) and ground. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Black/Tan wire.
11. Remove jumper wire. Using a DVOM, measure resistance between multifunction switch terminals No. 4 and 2 (component side). If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, replace multifunction switch.
12. Disconnect wiper motor connector. Using a jumper wire, connect wiper motor connector terminal No. 1 (Brown/White wire) to ground. Measure resistance between multifunction switch connector terminal No. 17 (Brown/White wire) and ground. If resistance is more than 5 ohms, repair open or high resistance in Brown/White wire. If resistance is less than 5 ohms, reconnect all connectors and retest system.