DESCRIPTION
| WARNING | To avoid injury from accidental air bag deployment, read and carefully follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY article in the ACCESSORIES/SAFETY EQUIPMENT section. |
Heater system is a bi-level type. Outside air enters heater system through cowl grille and passes through plenum chamber to heater unit. Blend-air door, located inside heater unit, routes incoming air through or past heater core. Amount of blended air is controlled by temperature control lever. Air distribution is controlled by mode selection and blower speed.
Some FWD vans are equipped with a rear-mounted auxiliary heater unit. Auxiliary rear heater control is located in rear quarter panel. System is a manually-operated, hot water device controlled by rear seat occupant. Rear heater control operates in conjunction with front heater control. A 4-position blower (override) switch is located on instrument panel. Operator of vehicle can use rear heater blower instrument panel switch to operate blower at HI or LO speed regardless of setting of rear control. Rear control will function when rear heater blower instrument panel switch is in on position and will not function when switch is in off position. Amount of heat produced by this unit is regulated by coolant flow through auxiliary heater control valve. A blower motor circulates heated air which has passed through heater core. (Scheme 1)
Scheme 1
Control panel has a mode lever which selects airflow direction. A temperature control lever adjusts amount of warm air entering system. Blower switch on control panel has 4 blower speed selections. (Scheme 2)
Scheme 2
Auxiliary heater unit has its own blower speed control switch which is operational only when dash mounted rear heater switch is in on position. (Scheme 2) With the dash switch in on position, rear blower motor can be controlled by auxiliary rear heater control panel. A cable-operated temperature control lever is also located in auxiliary rear heater control panel.
TEMPERATURE CONTROL CABLE ADJUSTMENT
- Temperature cable is attached to heater control and heater assembly by a black, "T"-shaped, snap-in flag. Rib provides installation orientation and retention. Flag may be removed only after tab has been depressed into receiver. (Scheme 3)and (Scheme 4).
- To adjust cable, place a 3/16" diameter rod into crank pin access hole and rotate clip from cable. Place temperature control lever in far left (cool) position. While allowing self-adjusting clip to slide on cable, rotate blend-air door crank counterclockwise by hand until it stops.
Scheme 3
Scheme 4
TOO MUCH HEAT
Blend-air door or temperature door binding or misdirected. Improperly adjusted, disconnected, kinked or broken temperature control cable. Thermostat stuck or opening at too high a temperature. Temperature door misdirected or binding.
BLOWER DOES NOT OPERATE AT ALL SPEEDS
Faulty resistor block or blower switch. Defective wiring connections at resistor block and/or blower switch.
BLOWER INOPERATIVE
Fuse blown. Motor inoperative. Faulty ground wire or blower switch. Open in motor or resistor.
BLOWER OPERATES ON HIGH SPEED ONLY
Fuse blown. Short in wiring. Defective resistor block or resistor switch.
INSUFFICIENT HEAT
Obstructed outlets. Temperature door binding or misadjusted. Kinked or unattached temperature control cable. Mode door binding or improperly adjusted. Mode door unattached. Kinked or plugged heater hoses. Heater core plugged. Defective heater control valve. Engine temperature low. Air in heater core. Hose connections reversed. Insufficient coolant.
REMOVAL & INSTALLATION
| WARNING | To avoid injury from accidental air bag deployment, read and carefully follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY article in the ACCESSORIES/SAFETY EQUIP section. |
MAIN HEATER CORE R & I
- Drain engine coolant. Disconnect negative battery cable. Disconnect heater hoses at heater core. Plug heater core tube openings. Remove steering wheel cover. Remove lower reinforcement from under steering column. Remove driver-side cowl.
- Remove bolt from passenger-side cowl to instrument panel. Loosen 2 brackets supporting heater housing. Remove instrument panel mid-reinforcement trim molding. Remove lower passenger-side instrument panel mounting screws. Disconnect vacuum lines at brake booster.
- Remove 4 heater housing mounting nuts. Pull lower passenger-side instrument panel toward passenger compartment until panel reaches passenger seat. Disconnect blower motor, resistor and temperature control cable. Remove hanger strap from package, and bend strap rearward.
- Remove package tray rearward from instrument panel, and remove tray from vehicle. Remove cover mounting screws. Remove heater core from housing. To install, reverse removal procedure.
MAIN BLOWER MOTOR R & I
Disconnect 2-way connector at blower motor lead. Remove blower motor attaching screws. Allow blower assembly to drop down. Remove blower motor from vehicle. To install, reverse removal procedure.
MAIN CONTROL PANEL R & I
- Remove 3 attaching screws from top of bezel. Remove ashtray. Remove 2 screws at lower edge of bezel. Pull bezel rearward to unsnap clip at left side of bezel. Remove bezel.
- Remove 2 screws fastening control base to instrument panel. Withdraw control panel from dash until cable and electrical and vacuum connections are accessible.
- Disconnect control cable from heater control. Remove vacuum lines from base of control push button switch. Remove electrical connectors. Remove control panel. To install, reverse removal procedure.
TEMPERATURE CONTROL CABLE R & I
Remove control panel to access cable attachment. Depress tab on flag, and pull flag out of receiver on control panel. (Scheme 3)and (Scheme 4). Remove cable from control assembly. Pull cable out from heater assembly. To install, reverse removal procedure. Adjust temperature control cable. See TEMPERATURE CONTROL CABLE ADJUSTMENT.
AUXILIARY HEATER UNIT R & I
- Drain cooling system. Disconnect auxiliary rear heater hoses from pipes under vehicle. Remove trim panel of left rear quarter panel.
- Remove 6 screws securing heater unit and ducts to floor pan. While guiding heater core tubes through floor opening, carefully lift heater unit from floor. To install, reverse removal procedure.
AUXILIARY HEATER CORE R & I
Drain engine coolant system. Disconnect rear heater tubing from underside of body. Remove trim panel from lower left quarter. Remove air distribution duct. Remove heater core cover. Pull heater core straight out of unit housing. To install, reverse removal procedure.
AUXILIARY BLOWER MOTOR R & I
- Remove trim panel from left lower quarter. Remove one blower cover-to-floor attaching screw. Remove 7 motor housing mounting screws. Remove blower relay attaching screw, and place relay out of work area.
- Rotate blower motor cover from under heater unit cover. Compress clamp at center of blower motor wheel. Pull wheel from blower motor shaft. Remove 3 blower motor attaching screws. Separate blower motor from unit. To install, reverse removal procedure.
AUXILIARY CONTROL PANEL R & I
- Carefully pry control panel bezel from quarter panel trim. Remove 4 screws attaching control panel to quarter trim, and separate control from trim panel.
- Locate and disengage locking tabs on temperature control cable. Remove cable from control panel. Disconnect wiring connector, and remove control panel. To install, reverse removal procedure.
