Blower Control Knob
Blower speed can be placed in 5 different levels from off (0) to high speed setting (4). The airflow to vent outlets is dependent on driving speed. (Scheme 26)
Temperature Control Knob
This knob, in center of control panel, allows the increase or decrease of temperature in passenger compartment. The knob controls the cable connected to temperature flap lever. (Scheme 26)
Air Distribution Knob
Airflow can be directed to windshield, upper body area, or to footwells. Intermediate positions are also possible. In the footwell position, a small amount of air flows to the windows to keep them from fogging up. (Scheme 26)
Scheme 26
COMPRESSOR
| CAUTION | If replacing compressor, follow instructions for compressor break-in or damage may occur. See step 10 . |
PIN VOLTAGE CHARTS
Pin voltage charts are supplied to reduce diagnostic time. Checking pin voltages at the A/C-heater control unit determines whether it is receiving and transmitting proper voltage signals. See the following A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS tables.
Note. All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with minimum 10-megohm input impedance.
| Pin No. | Function/Description | Signal Type | Connection |
|---|---|---|---|
| 1 | Terminal 15 | Input Signal | Heating Blower Relay |
| 2 | Activate Compressor Clutch | Output Signal | Instrument Cluster |
| 3 | Bower Level 1 (Air Conditioning) | Output Signal | Blower Resistor |
| 4 | Terminal 15 | Input Signal | Heating Blower Relay |
| 5 | Bower Level 1 (Air-Recirculation) | Output Signal | Blower Resistor |
| 6 | Ground For Function Lights | Ground | Ground Point |
| 7 | Terminal 15 | Input Signal | Heating Blower Relay |
| 8 | Activate Fresh Air-Recirculation | Output Signal | Fresh Air-Recirculation Motor |
A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS (Z3 - BLACK 8-PIN CONNECTOR X18349)
| Pin No. (1) | Function/Description | Signal Type | Connection |
|---|---|---|---|
| 2 | Ground | Ground Circuit | Ground Point |
| 3 | Climate-On-Signal | Input Signal | Air Conditioning/Recirculated Air Operating Unit |
| 5 | Activate A/C Compressor | Output Signal | Pressure Switch |
| 6 | Evaporator Temperature | Input Signal | Evaporator Temperature Sensor |
| (1) Pin assignments not listed are not used. | |||
| (1) | Pin assignments not listed are not used. |
A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS (Z3 - BLACK 6-PIN CONNECTOR X18350)
| Pin No. | Function/Description | Signal Type | Connection |
|---|---|---|---|
| 1 | Ground | Ground Circuit | Ground Point |
| 2 | A/C-On-Signal | Output Signal | Evaporator Controller |
| 3 | A/C-On-Signal | Output Signal | Normal Speed Relay |
| 4 | Terminal 15 | Input Signal | Heating Blower Relay |
| 5 | Blower Level 1 (Air Recirculation) | Output Signal | Blower Resistor |
| 6 | Function Light Ground | Ground Circuit | Ground Point |
| 7 | Terminal 15 | Input Signal | Heating Blower Relay |
| 8 | Activate Fresh Air-Recirculation | Output Signal | Fresh Air-Recirculation Motor |
A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS (M VEHICLES - BLACK 8-PIN CONNECTOR X18349)
| Pin No. (1) | Function/Description | Signal Type | Connection |
|---|---|---|---|
| 2 | Ground | Ground Circuit | Ground Point |
| 3 | Climate-On-Signal | Input Signal | Air Conditioning/Recirculated Air Operating Unit |
| 5 | Activate A/C Compressor | Output Signal | Pressure Switch |
| 6 | Evaporator Temperature | Input Signal | Evaporator Temperature Sensor |
| (1) Pin assignments not listed are not used. | |||
| (1) | Pin assignments not listed are not used. |
A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS (M VEHICLES - BLACK 6-PIN CONNECTOR X18350)
