Defogger Switch Circuit Test
- Turn ignition off. Remove defogger switch from console. Using an ohmmeter, check for continuity between ground and terminal No. 3 of defogger switch harness connector (harness side). See Fig 1
. If continuity is present, go to next step. If no continuity is present, heater circuit or heater element is faulty. Repair as necessary.
- Turn ignition switch to ACC position. Using a voltmeter, check for battery voltage between ground and defogger switch harness connector terminal No. 4. If battery voltage is present, circuit is okay. Go to DEFOGGER SWITCH TEST
under COMPONENT TESTING. If battery voltage is not present, check BACK-UP/TURN fuse and White/Green wire between fuse box and defogger switch for an open.
Courtesy of ISUZU MOTOR CO.