ELECTRIC COOLING FAN
Note. On models with A/C, electric cooling fans are also controlled by A/C system. See appropriate article in AIR CONDITIONING & HEATING.
Scheme 1
Scheme 2
- If cooling system needs refilling, ensure radiator and engine drain cocks are tight. Leaving air bleed valves open, connect length of clear hose to radiator and heater air bleed valves. Suspend other end of hose from hood and hood stay. (Scheme 1)and (Scheme 2).
- Ensure engine air bleed valve is open. Refill with 50/50 mix of ethylene-glycol based coolant and water. When coolant begins to flow out of engine air bleed valve, stop pouring and close engine air bleed valve.
- Ensure coolant level is at top of radiator cap filler neck. Ensure coolant level in suspended hoses are at the same level as the radiator cap filler neck. Close radiator and heater air bleed valves. Remove hoses.
- Install radiator cap to first stop point only. Start engine. Run at fast idle for about 3 minutes. Turn off engine. Recheck coolant lever. Refill coolant, if necessary.
- Install radiator cap. Fill coolant reservoir tank to "FULL" mark.
COOLING FAN QUICK TEST
- Ensure engine is cold. Turn ignition to "ON" position. Fan should not run. If so, check cooling fan relay, radiator fan switch and wiring.
- With ignition on, unplug radiator fan switch. Fan motor should operate. If not, check cooling fan relay, fan motor, engine main relay, fuse, and wiring. Connect radiator fan switch.
COOLING FAN RELAY
Cooling fan relays are located in engine compartment relay and fuse box. On all models except Camry V6, use (Scheme 3) as guide to test relay. On Camry V6, use (Scheme 4) to check "A/C FAN NO. 2" and "A/C FAN NO. 3".
Scheme 3
Scheme 4
ENGINE MAIN RELAY
Engine main relay supplies power to cooling fan relay. Relay is located in engine compartment relay and fuse box. On all models, use illustration as guide to test relay. (Scheme 5)
Scheme 5
FAN MOTOR
Unplug fan motor connector. Connect battery and ammeter to fan motor. Fan should operate smoothly and amperage draw should be within range. See FAN MOTOR AMPERAGE DRAW SPECIFICATIONS table.
| Model | Amps | ||
|---|---|---|---|
| Camry | |||
| 4-Cylinder | |||
| 2WD M/T | 3.2-4.4 | ||
| 2WD A/T & 4WD M/T | 5.8-7.4 | ||
| 4WD A/T | 8.8-10.8 | ||
| V6 | |||
| No. 1 Fan (Left Side) | 12.1-15.1 | ||
| No. 2 Fan | 6.0-7.4 | ||
| Celica | |||
| Non-Turbo M/T | 3.2-4.4 | ||
| Non-Turbo A/T | 5.8-7.4 | ||
| Turbo | 8.6-11.6 | ||
| Corolla | |||
| 4A-FE Engine With A/T | 8.8-10.8 | ||
| 4A-GE | 3.2-4.4 | ||
| All Others | 5.8-7.4 | ||
| MR2 | |||
| A/T | 8.8-10.8 | ||
| M/T | 5.8-7.4 | ||
| Tercel | |||
| A/T | 8.6-11.6 | ||
| M/T | 5.7-7.7 | ||
| Tercel EZ | 3.1-4.3 | ||
FAN MOTOR AMPERAGE DRAW SPECIFICATIONS
RADIATOR FAN SWITCH
- On all except MR2, radiator fan switch is located in upper radiator hose coolant inlet on engine. On all except Camry V6 and MR2, switch has single wire. On MR2, switch has 2 wires and is located on radiator tank.
- To test switch, remove switch from vehicle. Using ohmmeter, ensure continuity is correct between wire connector and switch body (or 2 switch terminals on MR2 and Camry V6). Switch may be gradually heated in water for testing. See «RADIATOR FAN SWITCH CONTINUITY (EXCEPT CAMRY V6)»(/toyota/supra/a70-1986-1993/remont/cooling-fan/#engine-cooling-systems) table or «RADIATOR FAN SWITCH CONTINUITY (CAMRY V6)»(/toyota/supra/a70-1986-1993/remont/cooling-fan/#engine-cooling-systems) table.
| Model | No Continuity °F (°C) | Continuity °F (°C) |
|---|---|---|
| Camry 4-Cylinder | Above 199 (93) | Below 181 (83) |
| Celica, Corolla & MR2 | Above 199 (93) | Below 181 (83) |
| Tercel | Above 192 (89) | Below 172 (78) |
| (1) As measured between between wire connector and switch body (or 2 switch terminals on MR2. | ||
| (1) | As measured between between wire connector and switch body (or 2 switch terminals on MR2. |
RADIATOR FAN SWITCH CONTINUITY (EXCEPT CAMRY V6) (1)
| Resistance Ohms | Temperature °F (°C) |
|---|---|
| 1530 | 176 (80) |
| 1180 | 194 (90) |
| 1030 | 203 (95 |
RADIATOR FAN SWITCH CONTINUITY (CAMRY V6)
Cooling Fan Relay Circuit
Cooling fan relay is located behind driver's side kick panel. Unplug relay connector. To check cooling fan relay circuit (Scheme 6)and LAND CRUISER COOLING FAN RELAY CIRCUIT TEST table.
| Wire Harness Terminal Check | Condition | Value |
|---|---|---|
| No. 1-Ground | Always | Continuity |
| No. 2-Ground | Ignition On | Battery Voltage |
| No. 3-Ground | Always | Continuity |
| No. 4-Ground | Always | Battery Voltage |
| No. 7-Ground | Always | Battery Voltage |
LAND CRUISER COOLING FAN RELAY CIRCUIT TEST
Scheme 6
Cooling Fan Motor Relay & Ignition Relay
To check relays (Scheme 7) Cooling fan motor relay is behind driver's side kick panel. Ignition relay is under left side of instrument panel in relay panel.
Scheme 7
Manifold Temperature Sensor
Manifold temperature sensor is located on intake manifold (single Blue wire). Remove sensor from intake manifold. Heat sensor slowly in water while checking continuity between wire terminal and sensor body. See LAND CRUISE MANIFOLD TEMPERATURE SENSOR SPECIFICATIONS table. Replace sensor if defective.
| Temperature °F (°C) | Resistance Ohms |
|---|---|
| 194 (90) | About 4000 |
| 230 (110) | About 2000 |
LAND CRUISER MANIFOLD TEMPERATURE SENSOR SPECIFICATIONS
Remove shroud from fan motor. Unplug fan motor. Connect 12-volt battery source and ammeter to fan motor terminals. Ensure fan motor rotates smoothly and current draw is 2.8-3.8 amps.
SYSTEM QUICK TEST
- Ensure engine coolant temperature is below 129°F (54°C). With ignition on and engine off, fan should not rotate. If fan operates, check fan relay, temperature sensor, and wiring.
- Unplug temperature sensor. Sensor is located on plate attached to rear of left side cylinder head. Fan should operate. If fan does not operate, check fan relay, fan motor, engine main relay, temperature sensor, and cooling fan computer.
- Plug in temperature sensor. Start engine. Run engine until coolant temperature is above 158°F (70°C). Fan should operate. If not, check temperature sensor and wiring.
Cooling Fan Computer Circuit
Cooling fan computer is located in right front corner of trunk. Unplug cooling fan computer connector. To check cooling fan computer circuit (Scheme 8)and MR2 COOLING FAN COMPUTER CIRCUIT TEST table.
| Wire Harness Terminal Check | Condition | Value |
|---|---|---|
| No. 1-Ground | Always | Continuity |
| No. 1-No. 3 | Ignition On | Battery Voltage |
| No. 4-No. 5 | Below 129°F (54°C) | More Than 600 Ohms |
| " | Above 158°F (70°C) | Less Than 415 Ohms |
| No. 1-No. 2 | Ignition On | Fan Warning Light "ON |
| No. 1-No. 6 | Ignition On | Fan Motor Runs & Warning Light "ON" |
| No. 1-No. 6 | Ignition On & Jumper Wire From No. 7 To No. 1 | Fan Motor Stops |
MR2 COOLING FAN COMPUTER CIRCUIT TEST
Scheme 8
Engine Main Relay & Fan Relay
Engine main relay and fan relay are located in fuse/relay block on left side of engine compartment. Remove relays from block. Use (Scheme 9) and (Scheme 10) as guide to test relays. Replace relay if defective.
Scheme 9
Scheme 10
Temperature Sensor
Temperature sensor is located on plate attached to rear of left side cylinder head (Blue/Red and Blue wires). Remove sensor. Heat sensor slowly in water while checking continuity between wire terminals. See MR2 TEMPERATURE SENSOR SPECIFICATIONS table. Replace sensor if defective.
| Temperature °F (°C) | Resistance Ohms |
|---|---|
| Less Than 129 (54) | More Than 600 |
| More Than 158 (70) | Less Than 415 |
MR2 TEMPERATURE SENSOR SPECIFICATIONS
Unplug fan motor connector. Connect 12-volt battery source and ammeter to fan motor terminals. Ensure fan motor rotates smoothly and current draw is 1.5-2.7 amps.
Scheme 11
Scheme 12
See also:
• FAN MOTOR AMPERAGE DRAW SPECIFICATIONS