Control Switch

NOTE: Thunderbird, Cougar XR-7, Ford, Mercury, Continental and Mark VI use a system which combines timer relay and control switch in one assembly. No separate switch testing is possible. Use the following procedure for all other models.

With switch in "NORM" position, test all terminals with ohmmeter. Continuity should exist between 2 terminals.
With switch in "ON" position, there should be continuity between all terminals. In "OFF" position, there should be no continuity.

Fig 1: Heated Rear Window Relay Connections Versailles, Fairmont, Zephyr

Courtesy of FORD MOTOR CO.