1994 MAZDA MX-5 heater

u INDEX INDEX HEATER 1. Heater unit Removal / Installation ......... page U-16 Disassembly / Assembly ...... page U-17 Inspection ................... page U-17 2. Blower unit Removal / Installation ......... page U-18 Disassembly / Assembly ...... page U-19 Inspection ................... page U-19 3. Heater control unit Removal / Installation ......... page U-20 Disassembly 1 Assembly ...... page U-21 Inspection ................... page U-22 Adjustment .................. page U-22 Gartner Banana

Ix-ozl MAIN FUSE eLOCK MAIN AD FAN IX-071 L/Y (€1 \ G-01 G -01 FRONT (F) -A/C IAC) G-02 MAGNETIC CLUTCH (F) G-03 BLOHER WIT (F) 16-04 ?$WER&TVRE SNITCt .CONDENSOR FAN .HEATER AND AIR CONDITIONER I I '07 CONENSOR FAN (AC) G-08 REFRIGERANT PflESSURE SWITCH (AC) IG-09 A/C RELAY (ACI 16- 10 COMENSER FAN RELAY (AC) Gartner Banana

TROUBLESHOOTING u TROUBLESHOOTING GUIDE I Symptom Blower motor does not operate Reference page Below Magnetic clutch does not operate I U-7 Condenser fan does not operate e Symptom: Blower motor does not operate I U-9 Insufficient cooling No cooling Intermittent cooling Normal operation of blower motor Blower motor speed is controlled by the fan switch and a resistor in the blower unit. When the fan switch L is in the OFF position, the motor ground circuit is open and the blower motor does not operate. When the switch is in the first (Low) position, current flow from the blower motor is restricted by the three resis- tors in the resistor, and the blower motor turns at low speed. Changing the fan switch to the second (Mid), third (high), or fourth (Super-high) position causes the cir- cuit resistance to decrease, and the blower motor speed becomes correspondingly faster. I l U-10 (-1 (rn) I I I RESET BUTTON FUSE BLOCK Step 1 1. Check the circuit breaker. 2. If the reset button is not out, go to Step 2. 3. If the reset button is out, check for a short circuit in the harness. Repair as necessary; then depress the reset button to reset the circuit breaker. circuit breaker HEATER Step 2 1. Turn the ignition switch to ON. 2. Turn the fan switch to the fourth position. 3. Measure the voltage at the A terminal wire of the blower motor connector. B+: Battery positive voltage I Terminal I Voltage Action I Amperage 30A Location Fuse block A U-5 Bt Other Go to Step 3 Repair wiring harness (Circuit breaker - Blower motor) Gartner Banana

HEATER u HEATER STRUCTURAL VIEW 1. Heater unit 45UOUX401 3. Heater control unit Removal 1 Installation ......... page U-16 Removal I lnstallation ......... page U-20 Disassembly / Assembly ...... page U-17 Disassembly l Assembly ...... page U-21 Inspection ................... page U-17 Inspection ................... page U-22 2. Blower unit Adjustment .................. page U-22 Removal 1 Installation ......... page U-18 4. Cooling unit Disassembly I Assembly ...... page U-19 Removal I Installation ......... page U-30 Inspection ................... page U-19 Disassembly / Assembly ...... page U-31 w Note Even in vehicles not equipped with NC, there is a cooling unit. If it is necessary to remove this unit to service the heater, then be sure to reinstall the cooling unit into its original position after servicing is complete. Gartner Banana

u HEATER HEATER UNIT Removal / Installation 1. Remove the dashboard. (Refer to section S.) 2. Remove the heater unit as shown in the figure. 3. Install in the reverse order of removal. 7.9-10.7 Nm (80-110 kgfcm, 69.5--95.4 In+bf] 1. Heater hose U-16 45UOUX4 2. Heater unit Gartner Banana

HEATER u Disassembly / Assembly Disassemble and assemble as shown in the figure. 1. Heater core 2. Air mix door 3. Airflow mode door Inspection Heater core 1. Check the heater core fins for blockage. 2. If the fins are clogged, clean them. 3. Check the fittings for cracks or other damage. Replace the heater core if necessary. Gartner Banana

u HEATER BLOWER UNIT Removal / Installation 1. Remove the glove compartment. (Refer to section S.) 2. Remove the blower unit as shown in the figure. 3. Install in the reverse order of removal. 7.910.7 Nm (80-110 kof cm, 69.5-95.4 Inlbf) 1. Blower unit U-18 Gartner Banana

HEATER u Disassembly I Assembly is assemble and assemble as shown in the figure. 1. Blower motor 2. Resistor 3. Air intake door Inspection Blower motor 1. Verify that the blower motor runs when connecting bat- tery positive voltage to terminal A and grounding termi- nal B. 2. If the blower motor does not run, replace it. Resistor 1. Check for continuity between the terminals of the resis- tor. 1 Terminals Continuity I I C-LO I Yes I I C-Me I Yes I I C- Mh I Yes I I C-Hi I Yes I 2. If not as specified, replace the resistor. U-19 Gartner Banana