Power Mirrors — Buick Regal III (1988-1997)

DESCRIPTION

On all models except Brougham, one mirror control switch adjusts both left (driver's side) and right (passenger side) mirrors. Mirror select switch setting determines whether left or right mirror is adjusted.

Brougham models do not use mirror select switch. Two separate mirror control switches control left and right mirrors.

OPERATION

Each power mirror assembly contains 2 reversible motors: an up/down motor and a left/right motor. Mirror control switch reverses polarity of motor circuit to change direction of mirror movement. Each motor contains a self-resetting circuit breaker, which opens when mirror reaches its mechanical limit of travel.

TESTING

Note. Brougham testing information is not available from manufacturer.

CAUTION

When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN article in the GENERAL INFORMATION section before disconnecting battery.

Before performing following tests, ensure circuit ground, circuit harness wiring and circuit fuse are okay. Also, check that all circuit connections are clean and tight.

LEFT MIRROR DOES NOT OPERATE (ACHIEVA, GRAND AM & SKYLARK)

Disconnect left outside mirror drive unit connector. Place mirror select switch in Left position. Place mirror position switch in Up position. Connect test light between Light Green wire terminal "A" of left outside mirror drive unit connector and ground.
If test light does not light, check for open in Light Green wire. If Light Green wire is okay, replace outside mirror control switch. If test light comes on, ensure mirror position switch is in Up position. Connect test light between Light Green wire terminal "A" and Yellow wire terminal "C" of left outside mirror drive unit connector.
If test light does not light, check for open in Yellow wire. If Yellow wire is okay, replace outside mirror control switch. If test light comes on, place mirror position switch in Down position. Connect test light between Light Green wire terminal "A" and Yellow wire terminal "C" of left outside mirror drive unit connector.
If test light does not light, replace outside mirror control switch. If test light comes on, place mirror position switch in Left position. Connect test light between Light Green wire terminal "A" and White wire terminal "B" of left outside mirror drive unit connector.
If test light does not light, check for open in White wire. If White wire is okay, replace outside mirror control switch. If test light comes on, place mirror position switch in Right position. Connect test light between Light Green wire terminal "A" and White wire terminal "B" of left outside mirror drive unit connector.
If test light does not light, replace left outside mirror drive unit. If test light comes on, replace outside mirror control switch.

LEFT MIRROR DOES NOT OPERATE (CAMARO & FIREBIRD)

Place mirror select switch in Left position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, use voltmeter to measure voltage between Yellow wire terminal "C" and Light Green wire terminal "E" of outside mirror control switch connector.
If battery voltage is not present, replace outside mirror control switch. If battery voltage is present, toggle mirror position switch between Left and Right positions. Measure voltage between Light Blue wire terminal "D" and White wire terminal "F" of outside mirror control switch connector.
If battery voltage is not present, replace outside mirror control switch. If battery voltage is present, check for open or shorted wires and connections. If wires and connections are okay, replace left outside mirror drive unit.

LEFT MIRROR DOES NOT OPERATE (CENTURY, DEVILLE & FLEETWOOD)

Place mirror select switch in Left position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Light Blue wire terminal "C" and Yellow wire terminal "D" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, toggle mirror position switch between Left and Right positions. Backprobe between White wire terminal "B" and Light Blue wire terminal "C" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, check for open or shorted wires and connections. If wires and connections are okay, replace left outside mirror drive unit.

LEFT MIRROR DOES NOT OPERATE (CORVETTE)

Disconnect left outside mirror drive unit connector. Place mirror select switch in Left position. Move mirror position switch to Down position. Connect test light between Light Green wire terminal "B" of left outside mirror drive unit connector and ground.
If test light does not light, check for open in Light Green wire. If Light Green wire is okay, replace left outside mirror drive unit. If test light comes on, toggle mirror position switch between Up and Down positions. Connect test light between Light Green wire terminal "B" and Purple/White wire terminal "C" of left outside mirror drive unit connector.
If test light does not light, check for open in Purple/White wire. If Purple/White wire is okay, replace left outside mirror drive unit. If test light comes on, toggle mirror position switch between Left and Right positions. Connect test light between White wire terminal "A" and Purple/White wire terminal "C" of left outside mirror drive unit connector.
If test light does not light, check for open in White wire. If White wire is okay, replace outside mirror control switch. If test light comes on, replace left outside mirror drive unit.

LEFT MIRROR DOES NOT OPERATE (CUTLASS SUPREME/GRAND PRIX/REGAL)

Place mirror select switch in Left position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Yellow wire terminal "C" and Light Green wire terminal "E" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, toggle mirror position switch between Left and Right positions. Backprobe between Light Blue wire terminal "B" and White wire terminal "D" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, check for open or shorted wires and connections. If wires and connections are okay, replace left outside mirror drive unit.

LEFT MIRROR DOES NOT OPERATE (RIVIERA, TORONADO & TROFEO)

Place mirror select switch in Left position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Yellow wire terminal "C" and Light Green wire terminal "D" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, toggle mirror position switch between Left and Right positions. Backprobe between Light Blue wire terminal "A" and White wire terminal "G" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, check for open or shorted wires and connections. If wires and connections are okay, replace left outside mirror drive unit.

Caprice, Custom Cruiser & Roadmaster

Place mirror select switch in Left position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Light Green wire terminal "C" and Yellow wire terminal "D" of outside mirror control switch connector.
If test light does not light, check for poor connections at Light Green wire terminal and Yellow wire terminal of outside mirror control switch connector. If connections are okay, replace outside mirror control switch.
If test light comes on, toggle mirror position switch between Up and Down positions. With left outside mirror drive unit connector still connected, using test light, backprobe between Light Green wire terminal "C" and Yellow wire terminal "D" of left outside mirror drive unit connector.
If test light does not light, check for open in Light Green wire or Yellow wire between outside mirror control switch and left outside mirror drive unit. Repair or replace as necessary.
If test light comes on, check for poor connections at Light Green wire terminal and Yellow wire terminal of left outside mirror drive unit connector. If connections are okay, replace left outside mirror drive unit.

Place mirror select switch in Left position. Toggle mirror position switch between Left and Right positions. With outside mirror control switch connector still connected, using test light, backprobe between White wire terminal "B" and Light Green wire terminal "C" of outside mirror control switch connector.
If test light does not light, check for poor connections at White wire terminal and Light Green wire terminal of outside mirror control switch connector. If connections are okay, replace outside mirror control switch.
If test light comes on, toggle mirror position switch between Left and Right positions. With left outside mirror drive unit connector still connected, using test light, backprobe between White wire terminal "B" and Light Blue wire terminal "A" of left outside mirror drive unit connector.
If test light does not light, check for open in White wire or Light Blue wire between outside mirror control switch and left outside mirror drive unit. Repair or replace as necessary.
If test light comes on, check for poor connections at White wire terminal and Light Blue wire terminal of left outside mirror drive unit connector. If connections are okay, replace left outside mirror drive unit.

Place mirror select switch in Left position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Light Green wire terminal "C" and Yellow wire terminal "D" of outside mirror control switch connector.
If test light does not light, check for poor connections at Light Green wire terminal and Yellow wire terminal of outside mirror control switch connector. If connections are okay, replace outside mirror control switch.
If test light comes on, toggle mirror position switch between Up and Down positions. With left outside mirror drive unit connector still connected, using test light, backprobe between Light Green wire terminal "C" and Yellow wire terminal "D" of left outside mirror drive unit connector.
If test light does not light, check for open in Light Green wire between outside mirror control switch and left outside mirror drive unit. Repair or replace as necessary.
If test light comes on, check for poor connections at Light Green wire terminal and Yellow wire terminal of left outside mirror drive unit connector. If connections are okay, replace left outside mirror drive unit.

RIGHT MIRROR DOES NOT OPERATE (ACHIEVA, GRAND AM & SKYLARK)

Disconnect right outside mirror drive unit connector. Place mirror select switch in Right position. Place mirror position switch in Up position. Connect test light between Light Blue/White wire terminal "A" of right outside mirror drive unit connector and ground.
If test light does not light, check for open in Light Blue/White wire. If Light Blue/White wire is okay, replace outside mirror control switch. If test light comes on, place mirror position switch in Up position. Connect test light between Light Blue/White wire terminal "A" and Brown/White wire terminal "C" of right outside mirror drive unit connector.
If test light does not light, check for open in Brown/White wire. If Brown/White wire is okay, replace outside mirror control switch. If test light comes on, place mirror position switch in Down position. Connect test light between Light Blue/White wire terminal "A" and Brown/White wire terminal "C" of right outside mirror drive unit connector.
If test light does not light, replace outside mirror control switch. If test light comes on, place mirror position switch in Left position. Connect test light between Light Blue/White wire terminal "A" and Red/White wire terminal "B" of right outside mirror drive unit connector.
If test light does not light, check for open in Red/White wire. If Red/White wire is okay, replace outside mirror control switch. If test light comes on, place mirror position switch in Right position. Connect test light between Light Blue/White wire terminal "A" and Red/White wire terminal "B" of right outside mirror drive unit connector.
If test light does not light, replace right outside mirror drive unit. If test light comes on, replace outside mirror control switch.

RIGHT MIRROR DOES NOT OPERATE (CAMARO & FIREBIRD)

Place mirror select switch in Right position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, use voltmeter to measure voltage between Yellow wire terminal "C" and Light Green wire terminal "G" of outside mirror control switch connector.
If battery voltage is not present, replace outside mirror control switch. If battery voltage is present, toggle mirror position switch between Left and Right positions. Measure voltage between Light Blue wire terminal "D" and White wire terminal "H" of outside mirror control switch connector.
If battery voltage is not present, replace outside mirror control switch. If battery voltage is present, check for open or shorted wires and connections. If wires and connections are okay, replace right outside mirror drive unit.

RIGHT MIRROR DOES NOT OPERATE (CENTURY, DEVILLE & FLEETWOOD)

Place mirror select switch in Right position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Yellow wire terminal "E" and Light Blue wire terminal "F" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, toggle mirror position switch between Left and Right positions. Backprobe between Light Blue wire terminal "F" and White wire terminal "G" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, check for open or shorted wires and connections. If wires and connections are okay, replace right outside mirror drive unit.

RIGHT MIRROR DOES NOT OPERATE (CORVETTE)

Disconnect right outside mirror drive unit connector. Place mirror select switch in Right position. Move mirror position switch to Down position. Connect test light between Light Blue wire terminal "B" of right outside mirror drive unit connector and ground.
If test light does not light, check for open in Light Blue wire. If Light Blue wire is okay, replace right outside mirror drive unit switch. If test light comes on, toggle mirror position switch between Up and Down positions. Connect test light between Light Blue wire terminal "B" and Purple/White wire terminal "C" of right outside mirror drive unit connector.
If test light does not light, check for open in Purple/White wire. If Purple/White wire is okay, replace right outside mirror drive unit. If test light comes on, toggle mirror position switch between Left and Right positions. Connect test light between Red/White wire terminal "A" and Purple/White wire terminal "C" of right outside mirror drive unit connector.
If test light does not light, check for open in Red/White wire. If Red/White wire is okay, replace outside mirror control switch. If test light comes on, replace right outside mirror drive unit.

RIGHT MIRROR DOES NOT OPERATE (CUTLASS SUPREME/GRAND PRIX REGAL)

Place mirror select switch in Right position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Yellow wire terminal "C" and Light Green wire terminal "F" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, toggle mirror position switch between Left and Right positions. Backprobe between Light Blue wire terminal "B" and White wire terminal "G" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, check for open or shorted wires and connections. If wires and connections are okay, replace right outside mirror drive unit.

RIGHT MIRROR DOES NOT OPERATE (RIVIERA, TORONADO & TROFEO)

Place mirror select switch in Right position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Yellow wire terminal "C" and Purple/White wire terminal "E" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, toggle mirror position switch between Left and Right positions. Backprobe between Light Blue wire terminal "A" and Red/White wire terminal "F" of outside mirror control switch connector.
If test light does not light, replace outside mirror control switch. If test light comes on, check for open or shorted wires and connections. If wires and connections are okay, replace right outside mirror drive unit.

Place mirror select switch in Right position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Yellow wire terminal "E" and Light Blue wire terminal "F" of outside mirror control switch connector.
If test light does not light, check for poor connections at Yellow wire terminal and Light Blue wire terminal of outside mirror control switch connector. If connections are okay, replace outside mirror control switch.
If test light comes on, toggle mirror position switch between Up and Down positions. With right outside mirror drive unit connector still connected, using test light, backprobe between Yellow wire terminal "D" and Light Green wire terminal "C" of right outside mirror drive unit connector.
If test light does not light, check for open in Yellow wire or Light Green wire between outside mirror control switch and right outside mirror drive unit. Repair or replace as necessary.
If test light comes on, check for poor connections at Yellow wire terminal and Light Green wire terminal of right outside mirror drive unit connector. If connections are okay, replace right outside mirror drive unit.

Place mirror select switch in Right position. Toggle mirror position switch between Left and Right positions. With outside mirror control switch connector still connected, using test light, backprobe between Light Blue wire terminal "F" and White wire terminal "G" of outside mirror control switch connector.
If test light does not light, check for poor connections at Light Blue wire terminal and White wire terminal of outside mirror control switch connector. If connections are okay, replace outside mirror control switch.
If test light comes on, toggle mirror position switch between Left and Right positions. With right outside mirror drive unit connector still connected, using test light, backprobe between Light Blue wire terminal "A" and White wire terminal "B" of right outside mirror drive unit connector.
If test light does not light, check for open in Light Blue wire or White wire between outside mirror control switch and right outside mirror drive unit. Repair or replace as necessary.
If test light comes on, check for poor connections at Light Blue wire terminal and White wire terminal of right outside mirror drive unit connector. If connections are okay, replace right outside mirror drive unit.

Place mirror select switch in Right position. Toggle mirror position switch between Up and Down positions. With outside mirror control switch connector still connected, using test light, backprobe between Yellow wire terminal "E" and Light Blue wire terminal "F" of outside mirror control switch connector.
If test light does not light, check for poor connections at Yellow wire terminal and Light Blue wire terminal of outside mirror control switch connector. If connections are okay, replace outside mirror control switch.
If test light comes on, toggle mirror position switch between Up and Down positions. With right outside mirror drive unit connector still connected, using test light, backprobe between Light Green wire terminal "C" and Yellow wire terminal "D" of right outside mirror drive unit connector.
If test light does not light, check for open in Light Blue wire between outside mirror control switch and right outside mirror drive unit. Repair or replace as necessary.
If test light comes on, check for poor connections at Light Green wire terminal and Yellow wire terminal of right outside mirror drive unit connector. If connections are okay, replace right outside mirror drive unit.

ONE MIRROR DOES NOT OPERATE

Note. For outside mirror control switch connector terminal wire colors, see WIRE COLOR IDENTIFICATION table.

Bonneville, Eighty-Eight, Eldorado, LeSabre, Ninety-Eight, Park Avenue & Seville

Disconnect outside mirror control switch connector. Place mirror select switch and mirror position switch in Rest position. Using ohmmeter, check for resistance between terminals "A", "B" and "C" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Left position. Place mirror position switch in Rest position. Check for resistance between terminals "A", "B", "C", "D" and "E" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Left position. Place mirror position switch in Up position. Check for resistance between terminals "A", "B", "C", "D", "E" and "H" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Left position. Place mirror position switch in Down position. Check for resistance between terminals "A", "B", "C", "D", "E" and "H" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Left position. Place mirror position switch in Left position. Check for resistance between terminals "A", "B", "C", "D", "E" and "H" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Left position. Place mirror position switch in Right position. Check for resistance between terminals "A", "B", "C", "D", "E" and "H" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Right position. Place mirror position switch in Rest position. Check for resistance between terminals "A", "B", "C", "F" and "G" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Right position. Place mirror position switch in Up position. Check for resistance between terminals "A", "B", "C", "F", "G" and "H" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Right position. Place mirror position switch in Down position. Check for resistance between terminals "A", "B", "C", "F", "G" and "H" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Right position. Place mirror position switch in Left position. Check for resistance between terminals "A", "B", "C", "F", "G" and "H" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, place mirror select switch in Right position. Place mirror position switch in Right position. Check for resistance between terminals "A", "B", "C", "F", "G" and "H" of outside mirror control switch connector.
If continuity is not present, replace outside mirror control switch. If continuity is present, check for open or shorted wires and connections. If wires and connections are okay, replace defective left or right outside mirror drive unit.

Application		Color
Bonneville
"A"		Orange
"B"		White
"C"		Light Blue
"D"		Yellow
"E"		Yellow
"F"		Light Blue
"G"		Red/White
"H"		Black
Eighty-Eight, Eldorado, LeSabre
Ninety-Eight, Park Avenue & Seville
"A"		Black
"B"		Light Blue
"C"		Yellow
"D"		White
"E"		Light Green
"F"		Purple/White
"G"		Red/White
"H"		Orange

WIRE COLOR IDENTIFICATION

BOTH MIRRORS DO NOT OPERATE CORVETTE

Disconnect outside mirror control switch connector. Connect test light between Yellow wire terminal of outside mirror control switch connector and ground.
If test light does not light, check for open or short to ground in Yellow wire or for open CRUISE fuse. Repair or replace as necessary. If test light comes on, connect test light between Yellow wire terminal and Black wire terminal of outside mirror control switch connector.
If test light does not light, check for open in Black wire. Repair or replace as necessary. If test light comes on, use ohmmeter to check for continuity of Purple/White wire between outside mirror control switch connector and left outside mirror drive unit connector.
If continuity is not present, check for open in Purple/White wire. Repair or replace as necessary. If test light comes on, replace outside mirror control switch.

BOTH MIRRORS DO NOT OPERATE EXCEPT CORVETTE

Disconnect outside mirror control switch connector. Connect test light between Orange wire terminal of outside mirror control switch connector and ground.
If test light does not light, check Orange wire. Repair or replace as necessary. If test light comes on, connect test light between Orange wire terminal and Black wire terminal of outside mirror control switch connector.
If test light does not light, check Black wire. Repair or replace as necessary. If test light comes on, replace outside mirror control switch.

REMOVAL & INSTALLATION

CAUTION

On some models, momentary actuation of power window switch can cause window to move directly to fully open position. When working inside door, leave ignition off whenever possible.

Insert flat tool between switch plate and trim panel, and disengage spring clip. If switch plate is attached to trim panel with screws, remove screws. Disconnect outside mirror control switch electrical connector. To install, reverse removal procedure.

Removal

Disconnect negative battery cable. Pull mirror and backing plate assembly out of mirror housing. (Scheme 1) Remove jack screws from mirror backing plate. If equipped with left outside mirror defogger, cut wires at splice location.

Installation

If equipped with left outside mirror defogger, splice wires together at splice location. Snap jack screws into NEW mirror backing plate. Align jack screws-to-drive unit and drive unit swivel-to-pivot points on mirror backing plate. Push mirror and backing plate assembly into housing until assembly clicks into place.

Scheme 1

Scheme 1: Installation

Cover door to avoid damage to painted surface. Tape mirror, then break mirror glass. Remove broken glass from mirror frame. Wipe inside of mirror frame clean.

Remove paper backing from replacement mirror glass. Center mirror glass in mirror frame and firmly press into place.

Remove outside mirror face. See OUTSIDE MIRROR FACE under REMOVAL & INSTALLATION. (Scheme 1) Remove screws attaching outside mirror drive unit to mirror housing. Disconnect electrical connector. To install, reverse removal procedure.

Remove door trim panel. Remove water deflector (if necessary). Remove speaker (if necessary). Remove support brackets (if equipped). Disconnect electrical connector. Remove outside mirror assembly attaching nuts. Remove outside mirror assembly. To install, reverse removal procedure.

WIRING DIAGRAMS

See appropriate chassis wiring diagram in WIRING DIAGRAMS Section.

Power Mirrors Buick Regal III