Power Windows - Tailgate Buick Estate Wagon

DESCRIPTION

The power tailgate window is operated by both a dash panel switch and tailgate key switch. A self actuated block-out switch prevents window operation when tailgate is open. Block-out switch also actuates dash mounted warning light.

A reversible electric motor, with internal circuit breaker, operates the regulator which raises and lowers the window. A fuse panel circuit breaker provides added protection to the tailgate window circuit.

The tailgate window assembly consists of solid tempered safety plate glass, bolted to lower sash guide plate assemblies. These assemblies operate on dual vertical guide tubes located in the tailgate.

OPERATION

A dual-winding electric motor moves the tailgate power window up or down. The direction the motor runs depends on which winding (raise or lower) is supplied with voltage. The dash-mounted tailgate power window control switch and tailgate key switch determine which winding is supplied with voltage.

When either switch is turned to RAISE position and the tailgate block-out switch is closed, voltage is applied to the raise winding of tailgate power window motor. The motor runs and the tailgate power window goes up.

Voltage to lower the tailgate window is applied through the lower contacts of both switches to the lower winding of the tailgate power window motor.

When the tailgate is opened, the tailgate block-out switch prevents tailgate power window from being raised.

BLOCK-OUT SWITCH ADJUSTMENT

Loosen block-out switch retaining screw and adjust glass block-out switch to achieve a.039" (1 mm), clearance between block-out switch plunger and locking lever. (Scheme 1) To insure proper operation of switch and lock, adjustment operation must be performed with remote lever against remote lever stop.

Scheme 1

WINDOW NOT PARALLEL W/ SIDE/UPPER WEATHERSTRIP - ADJUSTMENT

Condition is caused by glass cocked in opening. To correct, loosen up-travel stops and inner panel cam and raise or lower right or left side of glass as required. (Scheme 2)

UPPER EDGE OF WINDOW TOO FAR INBOARD/OUTBOARD - ADJUSTMENT

Loosen tailgate window sash plate attaching nuts on right and left sides. With glass in full-up position, loosen belt trim support attaching bolts. Position belt trim support retainers against inner surface of glass and tighten bolts and nuts. (Scheme 2)

WINDOW TOO HIGH OR LOW IN UP POSITION - ADJUSTMENT

To correct, loosen up-travel stops and operate window to a position which establishes proper glass to upper weatherstrip contact. Tighten up-travel stop attaching bolts. (Scheme 2)

WINDOW MECHANISM BINDS - ADJUSTMENT

Ease of window operation and window stability depend on belt trim support retainer adjustment. (Scheme 2) Belt trim support retainers should contact glass throughout full up/down cycle of window. Slight variations in glass contour may cause retainer to lose contact with glass halfway through the cycle. This is okay, provided the result is not loose glass. Contact should be enough to stabilize glass but not restrict ease of window operation.

Scheme 2

WINDOW DOES NOT OPERATE

See BLOCK-OUT SWITCH TEST and POWER WINDOW MOTOR TEST under TESTING.

WINDOW DOES NOT RAISE

See BLOCK-OUT SWITCH TEST and POWER WINDOW MOTOR TEST under TESTING.

WINDOW DOES NOT LOWER

Refer to KEY SWITCH TEST , POWER WINDOW MOTOR TEST and also CONTROL SWITCH TEST under TESTING.

WINDOW INOPERATIVE WITH KEY SWITCH

Check for faulty PWR/ACCY circuit breaker(s) by operating power door locks (if equipped). See, under TESTING, KEY SWITCH TEST and POWER WINDOW MOTOR TEST .

WINDOW INOPERATIVE WITH DASH PANEL SWITCH

Check for faulty WDO circuit breaker by operating power windows (if equipped). Refer to, under TESTING, CONTROL SWITCH TEST and POWER WINDOW MOTOR TEST .

WINDOW OPERATES WITH TAILGATE OPEN

Adjust/replace tailgate block-out switch.

BLOCK-OUT SWITCH TEST

1. Put ignition switch in RUN position. Put tailgate power window control switch in RAISE position. Leave tailgate block-out switch connector connected and measure voltage at connector between Dark Blue wire and ground. If battery voltage is not present, check/repair Dark Blue and Light Blue wires for opens.
2. Move tailgate key switch to RAISE position. Again measure voltage between Dark Blue wire and ground. If battery voltage is not present, check/repair Dark Blue and Light Blue wires for opens.
3. With tailgate key switch still in RAISE position, measure voltage between Light Blue wire and ground. If battery voltage is not present, check tailgate block-out switch adjustment. If adjustment is correct, replace tailgate block-out switch. See «ADJUSTMENTS»(/buick/estate-wagon/1990-1990/remont/windows/#power-windows-tailgate) in this article.

POWER WINDOW MOTOR TEST

1. Close power window. Disconnect motor connector at motor. Place ignition switch in RUN position and move dash mounted tailgate window control switch to LOWER position.
2. Measure voltage between Tan/White wire at switch connector and ground. Repeat voltage measurement procedure with tailgate key switch in LOWER position. If battery voltage is not present in both tests, check/repair Tan/White wire for an open. If battery voltages are correct, replace tailgate power window motor.
3. Move tailgate power window control switch to RAISE position. Measure voltage at switch connector between Light Blue wire and ground. Repeat procedure with tailgate key switch in RAISE position. If battery voltage is not present, check/repair Light Blue wire for an open. If voltages are correct, replace tailgate power window motor.

CONTROL SWITCH TEST

1. Put ignition switch in RUN position. With tailgate power window control switch connector connected, measure voltage between Pink wire at control switch connector and ground. If battery voltage is not present, check/repair Pink wire for an open.
2. Put tailgate power window control switch in RAISE position. Check voltage between Light Blue wire at control switch connector and ground. If battery voltage is not present, replace tailgate power window control switch.
3. Put tailgate power window control switch in LOWER position. Measure voltage between Tan wire at control switch connector and ground. If battery voltage is not present, replace tailgate power window control switch.

KEY SWITCH TEST

1. Leave tailgate key switch connector connected and measure voltage between Orange/Black wire at switch connector and ground. If battery voltage is not present, check/repair Orange/Black wire for an open.
2. Move tailgate power window key switch to RAISE position. Measure voltage at switch connector between Light Blue wire and ground. If battery voltage is not present, replace tailgate power window key switch.
3. Move tailgate power window key switch to LOWER position. At control switch connector, measure voltage between Tan wire and ground. If battery voltage is not present, replace tailgate power window key switch.

Removal

1. Open tailgate as a door with glass up. Remove inside remote handle, inner trim panel, water deflector and inner panel access hole covers. If equipped with heated tailgate glass option, disconnect wire harness.
2. Mark location of up-travel stop attaching bolts and belt trim support retainers. Loosen fasteners and move stops and supports away from glass. Manually latch left upper hinge lock. (Scheme 3) WARNING: With tailgate open and left upper hinge lock manually engaged, tailgate can drop from right lower lock if locking rod or outside handle is activated. Do not activate handle or rods. Personal injury or damage to tailgate may result.
3. Operate tailgate window until regulator cam attaching nuts are visible through holes in inner panel. Remove regulator cam attaching nuts. (Scheme 2) Working through left and right access holes, remove sash plate attaching nuts. (Scheme 2) Remove window through belt opening.

Installation

To install, reverse removal procedure. Lubricate motor drive gear and regulator sector gear with cold weather approved White lithium grease. Grease must be approved to a minimum of -20° F (-29° C). Ensure drive gear engages properly with regulator teeth.

Scheme 3

REGULATOR ELECTRIC MOTOR

Removal (Glass Intact & Attached To Regulator)

1. Open tailgate as a door with window up. Remove inside remote handle, inner trim panel, water deflector and left access hole cover. Remove wire harness from regulator motor. Drive center pin out of motor rivet with punch. (Scheme 2)
2. Drill out motor rivet using a 1/4" drill bit. Remove bolts attaching regulator motor by working through left access hole. Remove regulator motor through left access hole.

To install, reverse the removal procedure. Lubricate both the motor drive gear and regulator sector gear with cold weather approved White lithium grease. Grease must be approved to a minimum of -20° F (-29° C). Use a "U" nut and 1/4" x 20 x 1/2" screw in place of drilled out rivet.

Removal (Glass Broken Or Not Attached To Regulator)

1. Open tailgate as a door. Remove remote handle, inner trim panel, water deflector and inner panel access hole covers. With window in full-up position, mark the position of bolts at belt trim support retainers. (Scheme 2)
2. Drill a 1/8" hole through regulator gear and backplate. Install a pan head sheet metal screw in hole to lock regulator gear in position. This procedure must be followed to restrain counterbalance spring tension and avoid the possibility of serious personal injury.
3. Loosen belt trim support retainer bolts. Mark location of inner panel cam attaching bolts. Support window. Remove inner panel cam attaching bolts. Remove regulator cam attaching nuts.
4. Remove window regulator cam from window. Remove electric motor wiring harness. Drive center pins from regulator rivets and motor rivet with a punch. Drill out the regulator and motor rivets using a 1/4" drill bit. Remove regulator and motor as an assembly through access hole.

To install, reverse removal procedure. If replacement regulator does not have attaching nuts, place "U" nuts in position over each attaching hole with integral nut on outboard side of regulator backplate. Replace rivets with 1/4" x 20 x 7/16" screws.

WIRING DIAGRAMS

See appropriate chassis wiring diagram in WIRING DIAGRAMS.

See also:
• BLOCK-OUT SWITCH TEST
• POWER WINDOW MOTOR TEST
• KEY SWITCH TEST
• CONTROL SWITCH TEST
• ADJUSTMENTS