Both Side Mirrors Inoperative
- Power & Ground Circuit Check
- Remove power mirror control switch and unplug harness connector. Measure voltage between mirror control switch connector Black wire (Pink/Orange wire on Town Car) and appropriate power wire. See POWER WIRE COLOR IDENTIFICATION TABLE. If battery voltage is present, go to step 6). If battery voltage is not present, go to next step.POWER WIRE COLOR IDENTIFICATION
Application Wire Color Sable & Taurus Dark Green - Ground Circuit Check - Disconnect mirror switch harness connector. Measure resistance between ground and mirror switch harness connector Black wire. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open Black wire. Reconnect harness connector and retest system.
- Power Supply Check - Turn ignition on. Measure voltage between ground and appropriate mirror switch harness connector power wire. See POWER WIRE COLOR IDENTIFICATION TABLE. If battery voltage is present, go to step 6). If battery voltage is not present, go to next step.
- Short To Ground Check - Turn ignition off. Remove power mirror system fuse. See WIRING DIAGRAMS , for fuse identification. Measure resistance between chassis ground and power wire at mirror switch harness connector. If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short to ground in power wire.
- Power Supply Circuit Continuity Check - Remove power mirror system fuse. See WIRING DIAGRAMS , for fuse identification. Check continuity of power wire between mirror control switch and fuse cavity. If resistance is 5 ohms or less, replace fuse and to next step. If resistance is more than 5 ohms, repair open in power wire and retest system.
- Mirror Function Check
- Unplug mirror control switch. Using fused jumper wires, check mirror operation by applying battery voltage and ground to appropriate wire terminals. See MIRROR FUNCTION TEST TABLE. Mirror should move in one direction. To move mirror in opposite direction reverse polarity of jumper wires. If mirrors operate in all directions, replace mirror control switch and retest system. If mirrors do not operate in all directions, go to next step.MIRROR FUNCTION TEST
Mirror Function Wire Color Right Mirror Up/Down Operation Purple & Yellow Left/Right Operation Red & Yellow Left Mirror Up/Down Operation Dark Blue & Yellow Left/Right Operation Red & Yellow - Mirror Circuit Continuity Check - Unplug mirror switch. Unplug harness connector at suspect mirror. See SIDE MIRROR ASSEMBLY under REMOVAL & INSTALLATION. Using ohmmeter, check continuity of each wire between mirror and mirror switch harness connectors. For wire color identification, see WIRING DIAGRAMS . Measure resistance between each wire at mirror harness connector and ground. If ohmmeter indicates any wire open or shorted to ground, repair open shorted wire(s). If all mirror circuits are okay, replace mirror motor.