Test C: Rear Defogger Grid Test

With Ignition Switch in RUN and Rear DEF Switch pressed on, connect one voltmeter lead to ground. From inside vehicle, lightly touch other lead to each Rear Defogger grid line, and slowly move it along length of grid. The voltage reading should decrease as voltmeter is moved from left (passenger's side) to right (driver's side).

^ If voltmeter reads no voltage along all of grid line, check PPL/WHT (293) wire to Relay Center for an open. If OK, check Rear Defogger grid pigtail connectors for opens or poor contact.
^ If voltmeter reads battery voltage at both grid ends, check BLK (152) wire for an open to ground. If OK, check Rear Defogger grid pigtail connectors for opens for poor contact.
^ If voltmeter suddenly reads no voltage as it is moved along grid, a break in grid line continuity exists.