Test A: One Or Both Side Mirrors Malfunctioning

1. Remove mirror control switch and disconnect harness connector. Measure voltage at terminal No. 3 (Orange/Yellow wire) at mirror control switch harness connector. See Fig 1 . If battery voltage exists, go to next step. If battery voltage does not exist, go to step 3).
2. Measure resistance between ground and terminal No. 5 (Black wire) at mirror control switch harness connector. If resistance is 5 ohms or less, go to step 5). If resistance is greater than 5 ohms, repair open Black wire.
3. Check fuse No. 34 (7.5-amp) in instrument panel fuse box. If fuse is okay, go to next step. If fuse is blown, repair short to ground in Orange/Yellow wire or power distribution circuit. See appropriate POWER DISTRIBUTION wiring diagram in SYSTEM WIRING DIAGRAMS article in the WIRING DIAGRAMS section.
4. Measure voltage at input side of fuse No. 34. If battery voltage exists, repair open in Orange/Yellow wire. If battery voltage does not exist, repair power distribution. See appropriate POWER DISTRIBUTION wiring diagram in SYSTEM WIRING DIAGRAMS article in the WIRING DIAGRAMS section.
5. Test mirror control switch. See MIRROR CONTROL SWITCH under COMPONENT TESTS. If switch is okay, go to next step. If switch is defective, replace mirror control switch.
6. Disconnect driver and passenger mirror harness connectors. Turn ignition switch to RUN position. Measure voltage at terminals at mirror control switch harness connector. See TERMINAL IDENTIFICATION table. If voltage does not exist at any terminal, go to next step. If voltage exists at any terminal, repair short to voltage in appropriate wire.
   TERMINAL IDENTIFICATION
   
   

   Terminal No.	Wire Color
   2	White/Blue
   4	White/Violet
   6	Yellow/Red
   7	White/Black
   8	White/Red

7. Ignition off. Measure resistance between ground and terminals at mirror control switch harness connector. See TERMINAL IDENTIFICATION table. If all resistance readings are greater than 10,000 ohms, go to next step. If any resistance reading is 10,000 ohms or less, repair short to ground in appropriate wire.
8. Measure resistance in wires between mirror control switch harness connector and mirror harness connector. See Fig 1 and Fig 2 . See CIRCUIT RESISTANCE TERMINAL IDENTIFICATION table. If any resistance reading is greater than 5 ohms, repair open in appropriate wire. If all resistance readings are 5 ohms or less, replace appropriate mirror assembly.

CIRCUIT RESISTANCE TERMINAL IDENTIFICATION

Mirror Terminal No.		Switch Terminal No.	Wire Color
Driver Side
2		6	(1)
4		8	White/Red
5		2	White/Blue
Passenger Side
2		6	Yellow/Red
4		7	White/Black
5		4	White/Violet
(1) Yellow/Red wire changes to Yellow wire between mirror control switch harness connector and driver mirror harness connector.

Fig 1: Identifying Mirror Control Switch Harness Connector Terminals

Courtesy of FORD MOTOR CO.

Fig 2: Identifying Driver & Passenger Mirror Harness Connector Terminals

Courtesy of FORD MOTOR CO.