Rear Wiper/Washer Switch

Check the continuity between the windshield wiper/washer switch terminals. Either a self-powered test lamp or an ohmmeter can be used to test windshield wiper/washer switch.
To detect marginal operation of the windshield wiper/washer switch, move the button of the windshield wiper/washer switch while each reading is taken.
If the windshield wiper/washer switch does not exhibit continuity or if poor continuity exists in any position of the windshield wiper/washer switch, replace the windshield wiper/washer switch.