Defogger Switch Test: Cr-V

Check for open fuse No. 17 (7.5-amp), in underdash fuse/relay box. Replace as necessary. Remove center panel from dash. Remove defogger switch from backside of center panel. See Figure. Using a DVOM, check for voltage between terminals B4 (Blue/Yellow wire) and B7 (Black wire) in each switch position by connecting battery power to terminal B1 (Black/Yellow wire). In OFF position, reading should be less than .4 volt. In ON position, reading should indicate battery voltage. Replace switch if readings are not as specified.