DESCRIPTION
Heater system is a blend-air type. Outside air enters heater through cowl grille and passes through plenum chamber to heater core. Temperature control door in plenum chamber directs incoming air either through or past heater core.
Blending is controlled by temperature control lever. Distribution of blended air is controlled by heater-defroster lever and blower speed switch. A bi-level system is used on Acclaim and Spirit. This increases upper level airflow capacity for better air distribution, which provides better side window and defroster capability.
Acclaim & Spirit
Push button controls are used to select vacuum routing to all doors in the system except blend-air door. Heater control valve and blend-air door are operated by temperature lever, independent of push buttons. Blower does not operate when "OFF" push button is depressed.
All Other Models
Lever and cable controls are used to operate heater. One cable operates the heater mode door. The other cable operates the blend-air door.
CONTROL CABLE ADJUSTMENTS
Mode control cable (except Acclaim & Spirit) and temperature control cable (all models) are attached to heater control by color coded, "T" shaped snap-in flags. A Red flag is used for temperature cable and a Yellow flag for mode control on all FWD models (except Acclaim and Spirit). A Black flag is used on temperature control cable on all RWD models, Acclaim and Spirit. Flag may be removed only after tab has been depressed into receiver. Control cables are attached to self-adjusting clip. (Scheme 1)
TEMPERATURE CABLE (ALL OTHER MODELS)
Position temperature lever on control panel to "COOL" position. Allow self-adjusting clip to slide on cable. Rotate blend-air door crank counterclockwise by hand until it stops.
Scheme 1
- Twist self-adjusting clip (on core wire) 2" from small loop at heater assembly. Route control cable through middle holes of brake support bracket and around main wiring harness.
- Align door crank pin with clip. At the same time seat cable flag in retainer and place clip over crank pin. Place mode control lever in "OFF" position.
- Attach cable core wire to control lever pin. Snap the cable housing into retaining clip. Install control panel if removed. Adjust cable by moving control lever to "DEFROST" position. Make sure it contacts right edge of bezel slot.
VACUUM CONTROL SYSTEM TEST
Note. Test of push button control panel determines proper connection and functioning of vacuum and electrical circuits. Prior to starting this test ensure that vacuum source hose is tight on its connection at engine intake manifold. It is possible for a system that works normally at low engine speeds to malfunction at high engine speeds and low vacuum.
- With 8 in. Hg applied and test probe blocked, disconnect engine vacuum source and insert vacuum tester probe in hose leading to control switch. Push "HEAT" button and watch vacuum gauge reading. Vacuum reading should drop until actuator has completed operation, and then return to 7 1/4-8 in. Hg. (Scheme 2)
- Repeat test pushing "OFF", "BI-LEVEL", "DEFROST", and "HEAT" buttons, allowing time for actuators to operate and vacuum to stabilize. Vacuum will drop below 8 in. Hg after each operation. Maximum allowable drop is 3/4 in. Hg.
- By-pass vacuum reservoir (if equipped). In the event of more than 3/4 in. Hg drop, recheck tester for exactly 8 in. Hg reading. Inspect fit of 7-port hose connector plug on heater control switch. NOTE: Do not use lubricant on switch ports or holes in plug due to possible damage to vacuum valve in switch. A drop or two of clean water may be used on connector plug holes to aid in positioning plug on switch ports.
- If vacuum drop is now within limits, proceed to overall performance test. If vacuum drop still exceeds 3/4 in. Hg, remove 7-port connector from switch and seal port No. 3 with finger to block source hose. Insert vacuum source alternately into each connector hole except No. 3.
- If vacuum gauge returns to 8 in. Hg after each actuator has operated, control is leaking and must be replaced. If excessive vacuum drop occurs at one or more holes in connector block, isolate faulty hose or actuator. Vacuum drop in excess of 3/4 in. Hg would not significantly affect engine operation.
- Vacuum leaks could interfere with proper heating operation at high speeds and during acceleration. Repair leaks in vacuum lines by cutting out leaking section and pushing cut ends of tube into short section of 1/8" inside diameter rubber hose.
Scheme 2
See MANUAL A/C-HEATER SYSTEMS section for heater core removal and installation. Procedures for heater only system not available.
All Others
- Disconnect battery negative cable and drain radiator. Disconnect blower motor wiring. From under heater assembly, depress tab on mode door and temperature control cables, pull flags from receivers and remove self-adjusting clip from door crank arms.
- Remove glove box assembly. Disconnect heater hoses on engine side of firewall. Plug hoses and heater core tubes. Remove hanger strap to heater assembly screw by reaching through glove box opening. Remove 2 heater assembly attaching nuts from engine compartment.
- On Daytona, remove 2 screws attaching demister adapter to the top of heater assembly. On all models, pull instrument panel outward just enough to allow heater assembly to slide out. Remove heater assembly. (Scheme 3) To install, reverse removal procedure.
Scheme 3
BLOWER MOTOR R & I
- Disconnect battery negative cable. Disconnect blower motor wiring connector. Remove left heater outlet duct screws and remove duct.
- Remove 4 screws retaining blower motor to assembly and remove blower motor with fan. To remove fan wheel from motor, remove spring type retaining ring from motor shaft and remove fan wheel. To install, reverse removal procedure.
CONTROL PANEL R & I
Remove 2 screws attaching heater control bezel to heater control. Remove bezel by rolling out and lifting up to free bezel locating tabs. Remove 2 heater control screws and slide control panel out enough to disconnect control cables and electrical connector. Remove heater control. To install, reverse removal procedure.
