1994 MAZDA MX-5 cooling

ENGINE COOLANT COOLANT PROTECTION SPECIFIC GRAVITY COOLANT TEMPERATURE "C (OF) 45UOEX-00 Coolant Protection Caution The engine has aluminum parts that can be dam- aged by alcohol or methanol antifreeze. Do not use alcohol or methanol in the cooling system. Use only ethylene-glycol-based coolant. Use only soft (demineralized) water in the coolant mixture. Water that contains minerals will cut down on the coolant's effectiveness. 1. Measure the coolant temperature and specific gravity with a thermometer and a hydrometer. 2. Determine the coolant protection by referring to the graph shown. If the coolant protection is not proper, add water or cool- ant. Antifreeze solution mixture percentage I Coolant protection I I Above -1 6°C (3°F) 1 65 1 35 1 1.054 1 REPLACEMENT Draining Above -26°C {-15°F) Above -40°C I-40°F} Warning Removing the radiator cap or the coolant drain plug while the engine is running, or when the en- gine and radiator are hot is dangerous. Scalding coolant and steam may shoot out and cause seri- ous injury. If may also damage the engine and cooling system. Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise to the first stop. Step back while the pressure escapes. When you're sure all the pressure is gone, press down on the cap-still using a cloth - turn it, and remove it. 1. Remove the radiator cap and loosen the drain plug. 2. Drain the coolant into a container. 3. Flush the cooling system with water until all traces of col- or are gone, then let the system drain completely. 4. Install the drain plug. 55 45 45 55 1.066 1.078 Gartner Banana

E ENGINE COOLANT REFILLING Use the proper amount and mixture of ethylene-glycol based coolant. (Refer to Coolant Protection, page E-5.) 1. Slowly pour the coolant into the radiator up to the coolant filler port. Filling pace: 1.0 L (1.1 US qt, 0.9 Imp qt}/min. max 2. Fill the coolant reservoir up to the FULL level. 3. Fully install the radiator cap. 4. Start the engine and let it idle until it warms up. 5. If the temperature increases beyond normal, there is ex- cessive air in the system. Stop the engine and allow it to cool; then repeat step 1-3. 6. Run the engine at 2,200-2,800 rpm for five seconds; re- peat several times. 7. Stop the engine and allow it to cool. Warning Remove the radiator cap or the coolant filler cap while the engine is running, or when the engine and radiator are hot is dangerous. Scalding cool- ant and steam may shoot out and cause serious injury. It may also damage the engine and cooling system. Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise to the first stop. Step back while the pressure escapes. When you're sure all the pressure is gone, press ii down on the cap -still using a cloth - turn it, and remove it. 8. Remove the radiator cap and check the coolant level. If the coolant level has dropped, repeat the procedure from step 1. Gartner Banana

RADIATOR CAP RADIATOR CAP INSPECTION Radiator Cap Valve 1. Remove foreign material (such as water residue) from between the radiator cap valve and the valve seat. 2. Attach the radiator cap to a radiator cap tester (commer- cially available) with the SST. Apply pressure gradually to 73.6-1 02 kPa (0.75-1 .O5 kgf/cm2, 10.7-1 4.9 psi). 3. Wait about 10 seconds. Verify that the pressure has not decreased. PREPARATION L SST Negative Pressure Valve 1. Pull the negative pressure valve to open it. Verify that it closes completely when released. 2. Check for damage on the contact surfaces and for cracked or deformed seal packing. 3. Replace the radiator cap if necessary. 49 9200 145 Adapter set, radiator cap tester Warning Remove the radiator cap or the coolant drain plug while the engine is running, or when the engine and radiator are hot is dangerous. Scalding cool- ant and steam may shoot out and cause serious injury. It may also damage the engine and cooling system. Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise to the first stop. Step back while the pressure escapes. When you're sure all the pressure is gone, press down on the cap - still using a cloth - turn it, and remove it. 05UOEX-014 For inspection of radiator cap valve For inspection of radiator cap valve 49 9200 147 Adapter B (Part of 49 9200 145) Gartner Banana

TROUBLESHOOTING GUIDE INSPECTION Check for correct fuel line pressure at idle Section B ACTION Go to next step - Yes High compression Check engine condition Carbon deposits Engine compression: 1,255-883 kPa 112.8-9.0 kgf/cm2, 182-128 psi)-300 rpm Section B Check for correct fuel line pressure at idle page F-110 Yes - No Check if fuel line pressure decreases when accelerating quickly Fuel line pressure: 265-314 kPa (2.7-43.2 kgf/cm2, 38-46 psi) (Vacuum hose to pressure regulator discon- nected) 0 If decreases, check for clogging between fuel pump and pressure regulator 0 If no decrease, go to next step Low pressure Check fuel line pressure while pinching fuel return hose 0 If fuel line pressure quickly increases, check pressure regulator page F-118 0 If fuel line pressure gradually increases, check for clog- ging between fuel pump and pressure regulator If not clogged, check fuel pump maximum pressure w page F-115 INSTALL CLAPS Check for correct ignition timing at idle IJ&T page F-76 Yes Check if ignition timing advances when accelerating o If advances, go to next step o If no advance, replace PCME LW page F-143 Ignition timing: 10" + lo BTDC No - Yes Adjust page F-76 Check for EGR system malfunction page F-124 Repair or replace Go to next step Go to next step Check if cooling system is OK Section E Yes No - Yes Repair or replace Thermostat Electric cooling fan Radiator ~3 Section E Section B Section E Try known good PCME and check if condition im- proves IJ&T page F-144 Replace PCME page F-143 Change fuel to another brand or use higher octane fuel Gartner Banana

ENGINE TUNE-UP ENGINE TUNE-UP PREPARATION L" SST r I I 16EOF2-012 BASIC INSPECTION Engine Oil 1. Remove the dipstick and check the engine oil level and condition. 2. Add or change oil as necessary. 49 B019 9AO System Selector Coolant (engine cold) For inspection of ignition timing and idle speed Warning Removing the radiator cap or the coolant drain plug while the engine is running, or when the en- gine and radiator are hot is dangerous. Scalding coolant and steam may shoot out and cause seri- ous injury. It may also damage the engine and cooling system. Turn off the engine and wait until it is cool. Even then, be very careful when remov- ing the cap. Wrap a thick cloth around it and slow- ly turn it counterclockwise to the first stop. Step back while the pressure escapes. When you're sure all the pressure is gone, press down on the cap-still using a cloth-turn it, and remove it. 1. Verify that the coolant level is near the radiator filler neck. 2. Verify that the coolant level on the coolant dipstick is be- tween the F and L marks. 3. Add coolant if necessary. Battery Removing the label on the top of the battery or removing the vent caps will void the battery's warranty. 1. Clean any corrosion on the clamps or battery posts. 2. Verify that the battery top is clean. If necessary, clean with baking soda and water. 3. Verify that cables are in good condition and not frayed or corroded. Repair or replace if necessary. 4. Verify that cable clamps are tight. Note Because this is a maintenance free battery, it is not necessary to check the fluid level. Gartner Banana

COOLANT FAN CONTROL SYSTEM INSPECTION 1. Connect the SST to the data link connector. 2. Set switch @ to position 1. 3. Set the test switch to SELF-TEST. 4. Turn the ignition switch ON. 5. Rotate the throttle link by hard and verify that coolant fan and condenser fan operates. 6. Disconnect the SST. 7. If not specified, inspect as following. (Refer to page F-145.) PCME 1 N terminal voltage PCME 2H terminal voltage Coolant fan relay Condenser fan relay COOLANT FAN RELAY lnspection 1. Remove the coolant fan relay 2. Check continuity between the terminals of the relay. CONDENSER FAN RELAY 3. If not specified, replace the cooling fan relay. B+: Battery positive voltage CONDENSER FAN RELAY Inspection 1. Remove the condenser fan relay. 2. Check continuity between the terminals of the relay. i/ Terminal A - B Apply B+ B+ not applied 3. If not specified, replace the condenser fan relay. Terminal C - D Yes No B+: Battery positive voltage Terminal A - I3 Apply B+ B+ not applied Terminal C - E Yes No Gartner Banana

FUSE SPECIFICATIONS Main Fuse Block u I Fuse Amperes Protected circuit HEAD INJ MAIN BTN 30A 30A COOLING FAN (AD FAN) 1 ABS I 60A I Antilock brake svstem I Headlight relay, Headlight switch Alternator, Diagnostic module (for air bag system) 80A 40A ST SIG RETRACTOR Fuse Box No.1 Except circuits protected in main fuse block: INJ 30A, HEAD 30A, RETRACTOR 30A TNS relay, Headlight switch 30A 20A EGI main relay, Coolant fan relay A/C relay 10A 30A Park l Neutral switch, Circuit-opening relay Retractable headlight actuator Fuse ENGINE METER (POWER WIND) Amperes 15A WIPER TAIL ROOM I 10A I PCME, Key reminder switch, Audio unit I Protected circuit EGI main relay, Coolant fan relay 15A 30A STOP HAZARD CIGAR 15A I Cigarette lighter, Audio unit 1 Instrument cluster, Turn signal switch, Timer and buzzer unit, Cruise control main switch Power window switch 20A 15A Fuse Box No.2 Blower switch, Wiper switch Taillights, Side marker lights, License plate lights, Parking lights 15A 15A Fuse Amperes Protected circuit I Stoplight switch, Horn switch, Cruise control unit Flasher unit Fuse Color Code (DEFOG) (ANTENNA) I Fuse amperes I Color code Fuse type 25UOTX-013 20A 20A I I 10A Red 1 I Rear window defroster Power antenna Plate type 15A 20A Light blue Yellow 30A 30A 80A Light green Pink Black Cartridge type 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