1994 MAZDA MX-5 Workshop Manual

INDEX u AIR CONDITIONER 1. Cooling unit 5. Condenser fan relay ................... Removal 1 Installation ......... page U-30 Inspection page U-37 Disassembly I Assembly ...... page U-31 6. A/C compressor 2. Condenser Removal 1 Installation ......... page U-38 ...... Removal I Installation ......... page U-33 Disassembly I Assembly page U-41 3. Receiver drier 7. Magnetic clutch Removal I Installation ......... page U-33 Disassembly 1 Assembly ...... page U-39 4. AIC relay Inspection ................... page U-37 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

u TROUBLESHOOTING Step 3 1. Turn the ignition switch to ON. 2. Turn off the fan switch and ACS. 3. Measure the voltage at the terminal-wires of the resistor. u B+: Battery positive voltage I Terminal I Voltage I Action A (1-pin connector) A B C Step 4 1. Turn the ignition switch to ON. 2. Turn the fan switch to the fourth position. 3. Measure the voltage at the G terminal wire of the fan switch connector. .J B+: Battery positive voltage B+ , Other D CheckA terminal Replace blower motor B+ Other B+ Other B+ Other Step 5 1. Turn the ignition switch to ON. 2. Turn off the fan switch and ACS. Check B terminal Replace resistor Check C terminal Replace resistor Check D terminal Reolace resistor B+ Other Terminal G 3. Measure the voltage at the terminal-wires of the fan switch connector. Go to Step 4 Replace resistor B+: Battery positive voltage - Voltage B+ Other Action Repair wiring harness (Fan switch - GND) Go to Step 5 Gartner Banana

TROUBLESHOOTING u 7- Symptom: Magnetic clutch does not operate I Normal operation of magnetic clutch The PCME controls the operation of the condenser fan and magnetic clutch, depending on engine load. (Refer to section F.) The magnetic clutch is supplied with battery positive voltage as follows: 1. The ACS and fan switch are turned on. 2. The PCME receives a signal that the ACS and fan switch are on and creates a ground circuit. 3. The A/C relay is magnetized and the contact is closed. 4. Battery positive voltage is applied to the magnetic clutch and the clutch locks. WIPER 20A AD FAN 20A FUSE BLOCK MAIN FUSE BLOCK Step 1 1. Check the following fuses. I Fuse I Amperage I Location I I I . - I WIPER I 20A 1 In fuse block I I AD FAN I 20A 1 In main fuse block I 2. If the fuses are OK, go to Step 2. 3. If a fuse is burned, check for a short circuit in the harness before replacing it. Step 2 1. Run the engine at idle. 2. Turn on the ACS and fan switch. 3. Measure the voltage at the A terminal wire of the mag- netic clutch connector. B+: Battery positive voltage I Terminal I Voltage I Action 1 Step 3 1. Start the engine. 2. Turn on the fan switch and ACS. 3. Measure the voltage at terminal C and A of the A/C relay connector. B+: Batterv positive voltaae - -- A 1 Terminal I V0lta0e 1 Action I I C I Other I Repair wiring harness (AD FAN 20A fuse - AIC relay) I B+ Other I 1. -. B+ I GO to step 4 Replace magnetic clutch Go to Step 3 I A 1 Other I Repair wiring harness (WIPER 20A fuse - AIC relay) I Gartner Banana

u TROUBLESHOOTING Step 4 1. Remove the relay. 2. Apply battery positive voltage and check for continuity between the relay terminals. B+: Battery positive voltage 0---0 : Continuity I I I 45U0UX-013 3. If correct, repair wiring harness (AC relay - magnetic clutch). 4. If not as specified, replace the A/C relay. 1 0 10 I I I 2 1 B+ 1 GND 1 0 I Gartner Banana

TROUBLESHOOTING u Symptom: Condenser fan does not operate Normal operation of condenser fan The PCME controls the operation of the condenser fan and magnetic clutch, depending on engine load. (Refer to section F.) The condenser fan is supplied with battery positive voltage as follows: 1. The ACS and fan switch are turned on. 2. The PCME receives a signal that the ACS and fan switch are on and creates a ground circuit. 3. The A/C relay is magnetized and the contact is closed. 4. Battery positive voltage is applied to the condenser fan and the fan operates. Step 1 1. Turn the ignition switch to ON. 2. Measure the voltage at terminal A (B/Y) of the condenser fan connector. B+: Battery positive voltage Step 2 1. Disconnect the condenser fan connector. 2. Check for continuity between terminal B (B) of the con- denser fan connector and ground. Voltage B+ Other I GO to step 3 Action Go to Step 2 I continuity I Action I Step 3 1. Remove the condenser fan relay. 2. Apply battery positive voltage and check for continuity between the relay terminals. B+: Battery positive voltage Yes No Replace condenser fan Repair wiring harness (Condenser fan - GND) M: Continuity - - - 3. If correct, go to Step 4. 4. If not as specified, replace the condenser fan relay. 1 0 2 B+ Step 4 Check for continuity between terminal A (BN) of the con- denser fan connector and terminal C (BN) of the con- denser fan relay connector. I Continuity I Action 1 Repair wiring harness (Condenser fan relay - Fuse) B 0 GND I Repair wiring harness (Condenser fan - Condenser fan relay) I C 0 0 E 0 F 0 Gartner Banana

TROUBLESHOOTING I ltem 1 Symptom Symptom: lnsuff icient cooling No cooling Intermittent cooling Ill Bubbles present in sight glass u Immediately after air conditioner turned off, refrigerant in sight glass stavs clear I. When air conditioner turned off, re- frigerant foams, and then sight glass becomes clear No bubbles present in sight glass Step 1 Checking refrigerant charge 1. Run the engine at a fast idle. 2. Operate the air conditioner at maximum cooling for a few minutes. 3. Observe the sight glass to determine the amount of re- frigerant and the related action as shown below. Amount of refrigerant Action Insufficient refrigerant Too much or proper amount of refrig- erant Too much refrigerant Step 2 Checking refrigerant pressure 1. Connect the manifold gauge set. 2. Operate the engine at 1,500 rpm and set the air condi- tioner to maximum cooling. 3. Measure the refrigerant pressure. 1 Proper amount of refrigerant Normal pressure Low-pressure side: 0.1 5-4.24 MPa (1.5--2.5 kgf/cm2, 22--35 psi) High-pressure side: 1.38-1.56 MPa (1 4.0-1 6.0 kgf/cm2, 200-227 psi) Check refrigerant pressure, go to Step 2 Turn air conditioner off, and watch bubbles (Refer to Items 3 and 4) Check refrigerant pressure, go to Step 2 Refrigerant amount normal 4. If the pressures not as specified, refer to the chart on the next page and check the system. ,d Gartner Banana