Intermittent Wiper Switch Circuit

Turn ignition switch to the ON position and wiper switch to INT position. Using voltmeter, backprobe TCU connector. Connect positive voltmeter lead to terminal No. 12 and negative lead to terminal No. 15. Voltage should be zero. With wiper switch in the OFF position, battery voltage should be present. If test results are okay, replace TCU. If test results are not okay, check wiper switch. See WIPER/WASHER SWITCH.