heater MAZDA MX-5 1994 User Guide

nia (i' [-I PACL LIGHT '-6 1.4k HEATER CDNTRCL CONTROL X3 SWITCH SWITCH ILLMI1UATIONS 1 -a? .ILLUMINATION LIGHTS WARNING I CRUISE CCNTQOL ILLVMINATION -0l PANEL LIGHT CONTROL SWITCH (I1 I 1-02 HEATER CONTROL SWITCH ILLGMINA~IONS (11 11-03 ASHTRAY ILLUMINATION (I) H-06 AT SELECT ILLUMINATION(II I -07 HAZARD WAWING AND RETRACTOFi SWITCH ILLUMINATION(II I-oz CRUISE CONTROL MAIN snITcn ILLWINATION (11 E-10 FRONT FOG LIGHT ANO REAR WIMOW DEFROSTER SUITCH ILLUMINATION (I) I Gartner Banana

REAR WINDOW DEFROSTER REAR WINDOW DEFROSTER STRUCTURAL VIEW 1. Rear window defroster L/ 2. Rear window defroster switch 3. Rear window defroster relay 4. Rear window defroster timer unit DESCRIPTION The rear window defroster switch is included in the heater control switch assembly. Gartner Banana

REAR WINDOW DEFROSTER T u Symptom: Rear window defroster does not operate. 9MUOTX-232 Step 1 1. Check the following fuses. I Fuse Amperage I Location I 2. If all the fuses are OK, go to Step 2. 3. If a fuse is burned out, replace it. Check and repair the wire harness, if necessary. R.DEF HEATER -- M: Continuity 20A 30A Step 2 1. Disconnect the rear window defroster relay. 2. Apply battery positive voltage and check for continuity between terminals of the relay. B+: Battery positive voltage 3. If correct install the rear window defroster relay and go to Step 3. 4. If not as specified, replace the rear window defroster relay. Fuse box No.2 Main fuse block Step 1 2 C Terminal D 0 GND B 0 B+ A 0 C 0 Gartner Banana

T REAR WINDOW DEFROSTER Step 3 1. Turn the ignition switch to on. 2. Turn the rear window defroster switch on. 3. Check the voltage at the terminal wires of the rear win- d dow defroster rday connector. B+: Battery positive voltage Terminal (uB) c (R) Step 4 Check if the heater operates in the first position. I Operation I Action I Voltage B+ other NG Repair wiring harness (Heater switch- Rear window defrostertimer unit) Action Check C terminal Repair wiring harness (HEATER fuse - Relav) B+ Other . , Go to Step 4 Go to Step 5 I Step 5 Check the voltage at the rear window defroster connec- tors. Check A terminal Repair wiring harness (DEFOG fuse - Relavl A (w) B+: Battery positive voltage B+ Other Terminal I Voltage I Action B+ I Check C terminal other If all above-mentioned parts are normal, replace the rear window defroster timer unit. Repair wiring harness (Defroster - Defroster timer unit) c (W) A (B) . B+ Other B+ Other Check A terminal Repair wiring harness (Relay- Defroster) Repair wiring harness (Defroster - GND) Repair defroster filament Gartner Banana

SRS AIR BAG SYSTEM T COMPONENT DESCRIPTION Component Air bag module Function Air bag system warning light Deploys air bag when current flows to integrated igniter Light illuminates or flashes if malfunction occurs in air bag system I EE with S-sensor, completes Circuit Clock spring I Ensures uninterrupted electrical connec- tion to air bag module while allowing turning of steering wheel Activated(closed) when crash impact de- Crash sensor Diagnostic module to infktor Activated(closed) when crash impact de- S-sensor 1 Monitors com~onents and harnesses in tected Acting with D-sensor, completes circuit to inflator Remark Located in instrument cluster Location: Driver side . . . . . . . . in steering wheel hub Passenger side . . . above the glove compartment Part of combination switch Located in front part of vehicle(left, right, and center) Located behind heater unit in passenger compartment Contains back-up battery air bag system Indicates system malfunction by flashing or illuminating air bag system warning light If warning light is bunt, sounds warning buzzer Detects short circuit between air bag module and ground or crash sensor rnal- function and melts system fuse to pre- vent unintended air bag deployment Gartner Banana

Before beginning any service procedure. refer to section T of this manual for I air bag system service warnings and audio antitheft system alarm conditions . HEATER AND AIR CONDITIONER SYSTEMS ....................................... INDEX U- 2 ................................... HEATER U- 2 AIR CONDITIONER ......................... U- 3 TROUBLESHOOTING ......................... U- 4 CIRCUIT DIAGRAM ......................... U- 4 TROUBLESHOOTING GUIDE ................ U- 5 ..................................... HEATER U-15 ........................ STRUCTURAL VIEW U-15 HEATER UNIT .............................. U-16 BLOWER UNIT ............................. U-18 HEATER CONTROL UNIT .................... U-20 AIR CONDITIONER ........................... U-23 PREPARATION ............................. U-23 STRUCTURAL Vl EW ........................ U-23 SERVICE WARNINGS ....................... U-24 SERVICE CAUTIONS ........................ U-24 REFRIGERANT SYSTEM SERVICE PROCEDURE .............................. U-25 COOLING UNIT ............................. U-30 CONDENSER AND RECEIVER DRIER ........ U-33 REFRIGERANT LINES ....................... U-35 CONDENSER FAN .......................... U-36 AIC RELAY ................................. U-37 ................... CONDENSER FAN RELAY U-37 REFRIGERANT PRESSURE SWITCH ......... U-37 NC COMPRESSOR ......................... U-38 45U0Ux-001 Gartner Banana

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