Disconnect the windshield wiper motor connector.

Test the wiper motor by connecting battery power to terminal No. 1 and ground to terminal No. 2 of the wiper motor. The wiper motor should run at low speed.

Test the wiper motor by connecting battery power to terminal No. 3 and ground to terminal No. 2 of the wiper motor connector. The wiper motor should run at high speed.

Connect an analog ohmmeter to terminals No. 2 and No. 4, and run the wiper motor at low or high speed. The needle of the ohmmeter should pulse. If the wiper motor does not run or fails to run smoothly, or there is no pulse, replace the wiper motor (A) or the wiper linkage.

Connect the windshield wiper motor connector.