DESCRIPTION
Power seats operate by toggle switches located on the seat side or in the door arm rest. Seat adjusters are powered by a 12-volt reversible motor with an internal circuit breaker. A 30-ampere plug-in circuit breaker also protects power seat wiring and mounts on fuse panel.
2-WAY POWER SEATS
These seats operate in forward and rearward directions only. A control switch energizes motor. A jack screw at each end of the motor shaft turns seat adjusters in the desired direction through a horizontal gear nut attached to seat adjuster.
6-WAY POWER SEATS
Two types are used. One type has 3 reversible motors that operate the seats. Front and back parts of the seat are operated by different motors and can be raised and lowered independently. The third motor controls forward-backward movement. Drive cables connect motors to gear nuts, which turn jack screws and adjusters at each side of seat.
In the second type, each seat uses a single motor with 3 solenoids, 6 drive cables and a transmission. One solenoid controls front vertical movement, one controls rear vertical movement and the other controls horizontal movement. The motor then moves the seat. Releasing the switch disengages the drive motor from the cables. An optional memory device is available on both types.
POWER RECLINING SEAT BACK
This feature is not available on all models. The system includes a motor under the seat, drive cable, actuator and control switch. The switch is on the seat edge or in the armrest. Power seat backs operate independently of other power seat adjustments.
SPORT SEAT
The sport seat is similar to the base seat except it can be adjusted to fit driver's body contour. The backrest lateral restraints (side bolsters) are power adjusted 15 degrees in or out. Lumbar support can be pneumatically adjusted from soft to firm by inflating the 3 compartments located in seatback cushion. Inflation of 3 compartment bladders is controlled by a pressure pump, 3 bleed down valves and a control located on the right bolster.
The seatback angle is power adjustable over a 12 degree travel by a control in the left bolster. The sport seat is available with a manual fore and aft adjustment or a 6-way power adjustment.
HORIZONTAL ACTUATOR
- Chucking can be corrected by adjusting the horizontal actuator and pinion gear to full mesh with the lower adjuster lower track rack gear. Operate seat to full up position and about 3/4 forward. Loosen horizontal actuator screws. (Scheme 1)
- Using a large screwdriver, press out on horizontal actuator (about 15-25 lbs.) and energize horizontal switch to move seat slightly fore and aft. This helps seat the horizontal actuator pinion gear teeth tight to the lower track rack gear teeth and eliminate free play between gear teeth. Tighten screws while maintaining outward pressure against horizontal actuators.
SEAT ADJUSTER PHASING
When installing power seat adjusters (except at back recliner), each pair of adjusters must be in phase with each other. When adjusters are out of phase, one adjuster will reach its maximum travel before the other, resulting in improper seat travel.
Horizontal Travel
Operate seat until one adjuster reaches full forward position. Detach horizontal drive cable from adjuster which has reached full forward position. Now operate seat forward until other adjuster reaches full forward position. Reconnect drive cable of first adjuster. Adjusters are now in phase.
Vertical Travel (Front or Rear)
- Operate seat until one adjuster has reached fully raised position at both front and rear vertical travel limits. Disconnect both front and rear vertical drive cables from adjuster which has reached fully raised position.
- Operate seat until other adjuster reaches fully raised position. Now reconnect cables of early adjuster. Seat should now be in phase. If not, repeat above procedure.
Scheme 1
Jerky Horizontal Operation
Improper lubrication of adjuster shoes and channels. Adjuster shoes too tight in upper channels. Adjuster horizontal actuator gear too tight to rack gear.
Horizontal Chuck or Looseness
Horizontal actuator improperly adjusted.
One Adjuster Will Not Operate Horizontally
Horizontal drive cable damaged or disconnected. Horizontal actuator inoperative.
One Adjuster Will Not Operate Vertically
Vertical drive cable disconnected or damaged. Vertical gear nut inoperative.
Both Adjusters Will Not Operate Horizontally And/Or Vertically
Inoperative horizontal and/or vertical solenoid in transmission. Damaged, broken or inoperable solenoid plunger, shaft, gear or drive gear.
Vertical Chuck or Looseness
Excessive clearance at vertical gear nut tension spring.
Power Seat Back Motor Operates, But Seat Back Does Not Move
Drive cable disconnected or broken. Damaged or broken reclining actuator gear nut. Reclining actuator disconnected from arm of the seat back lock or support. Incorrect seat back lock or support.
Power Seat Back Operation Jerky
Kink or damage to drive cable. Bind in reclining hinge arm. Damaged or bent jack screw. Damaged actuator gear nut. Insufficient lubrication. Jack screw stop nut is loose.
Inoperative Adjuster Motor
Check for shorted or open circuit between power source, switch or motor. Check for a defective adjuster motor.
Motor Operates But Adjusters Will Not Operate
Check for a shorted or open circuit between switch and solenoid. Check solenoid for defects.
Motor Operates But Adjusters Or Recliner Only Operate In One Direction
Check for a shorted or open circuit between one of the motor fields and control switch. Check for a defective field coil.
Removal & Installation
- Remove seat belt-to-floor anchor plate attaching bolts. Where required, remove door sill plates and turn carpet to gain access to adjuster-to-floor attaching bolts. Operate seat to full forward and up position. At rear of adjusters, remove adjuster-to-floor rear attaching bolts.
- Operate seat to full rearward and full rear tilt position. Remove front adjuster-to-floor pan nuts. Disconnect electrical wire harness under seat and remove seat. To install, reverse removal procedure.
Scheme 2
- Remove seat as previously outlined. Place seat upside down on bench. Disconnect drive cables at adjuster being removed. Squeeze the oblong connector to remove. On bucket seats, remove the motor support-to-adjuster bolt.
- Remove adjuster-to-seat bottom attaching bolts and remove seat adjuster. Note location of spacers (if equipped). To install, reverse removal procedure and check that seats are in phase.
Remove seat and place upside down. Remove trim on outside of seat for access to actuator. Unscrew reclining back drive cable from reclining actuator and detach cable from actuator. Remove pin securing reclining actuator coupling-to-hinge arm. Remove actuator. To install, reverse removal procedure.
Removal & Installation (2-Way Seat)
If seat is operable, move seat to midway position. Remove front seat adjuster-to-floor attaching bolts and tilt seat rearward. Remove lower drive cables from motor support bracket. Remove motor with bracket attached. Disassemble motor and bracket as a bench operation. To install, reverse removal procedure.
Removal & Installation (6-Way Seat)
- Remove front seat assembly and place upside down on clean surface. Disconnect wiring. On single-motor seats, remove transmission-to-support screws and cable end plate screws on transmission ends. Separate motor and transmission and disengage rubber coupling.
- On 3-motor seats, remove motor support-to-motor mounting bracket screw. Disconnect drive cables from adjusters, remove nut from motor retaining rod and remove motor. To install, reverse removal procedure and check phasing.
Disconnect battery ground cable. Remove 2 screws retaining left side control panel escutcheon. Pull escutcheon with switches attached out of armrest to gain access to connector. Remove defective switch from escutcheon and connector. To install, reverse removal procedure.
- Disconnect battery ground cable. Remove seat cushion and release bail clip from frame panel. Disconnect pneumatic tubing and electrical connector to lumbar control assembly. Remove hog ring at underside of seat to access control.
- Remove escutcheon plate and remove control assembly through bottom of seat cushion. Also, if necessary, the valve body can be replaced at this time. To install, reverse removal procedure.
- Disconnect battery ground cable. Remove seat cushion. Remove 4 bolts retaining cushion frame panel to adjuster. Disconnect electrical connector and remove seat from vehicle.
- Disconnect electrical and pneumatic harness connectors at motor. Remove motor and pump assembly to frame attaching parts. Remove motor from seat cushion frame. To install, reverse removal procedure. Check operation of motor and pump.
WIRING DIAGRAMS
For wiring diagrams, refer to appropriate chassis wiring diagram in WIRING DIAGRAMS section.