Engine Cooling Fan Mercury Topaz II

DESCRIPTION

Electric cooling fan system consists of a fan and electric motor attached to a fan shroud, located behind the radiator. System utilizes a cooling fan temperature switch. Vehicles equipped with air conditioning have a cooling fan controller and cooling fan relay. On Tempo and Topaz models with a standard heater, the cooling fan is powered through the cooling fan relay.

OPERATION

The electric cooling fan operates only when ignition switch is in the "RUN" position on Tempo and Topaz models. Cooling fan operates whenever cooling fan temperature switch is closed on Escort.

On A/C-equipped models, the cooling fan is controlled by a cooling fan controller and fan relay. Cooling fan motor is energized when A/C cycling pressure switch closes with the select lever in "A/C" or "DEFROST" position. The A/C clutch coil is energized once voltage is available at the fan motor and will cycle with the A/C clutch cycling pressure switch.

Cooling fan motor will stay energized as A/C clutch cycles if cycling pressure switch opening intervals are less than 2-3 minutes. If cooling fan temperature switch closes in A/C mode at 210°F (99°C), fan motor will run continuously until coolant temperature drops less than 193°F (89°C).

Two different cooling fan controllers are used. Proper fan controller must be used to obtain proper operation of the cooling system. Fan controller is identified with a color code and part number.

Cooling fan operates when engine coolant temperature exceeds 210°F (99°C) or when A/C is operated. When A/C low side pressure is low, the clutch cycling pressure switch signals the fan controller to cut off power to A/C clutch coil, cooling fan motor and throttle solenoid kicker.

Cooling fan controller on Escort is located under right side of instrument panel, in front of evaporator mounting bracket. On Tempo and Topaz, controller is mounted on right cowl panel under instrument panel and can be serviced through glove compartment opening.

TROUBLE SHOOTING

Note. For further wiring information, see appropriate article in MANUAL A/C-HEATER SYSTEMS section.

COOLING FAN CONTROLLER (MODELS WITH A/C)

If cooling fan controller is suspected of not operating properly, diagnosis can be performed by checking voltage readings at controller connector with controller plugged in. (Scheme 1)and (Scheme 2). Cooling fan controller is located under right side of instrument panel, in front of evaporator mounting bracket on Escort models or on right cowl panel under instrument panel on Tempo and Topaz models and can be serviced through glove compartment opening.

Scheme 1

Scheme 2

Note. If cooling fan controller pin voltage test indicates controller is not defective, follow these diagnostic procedures. These procedures can be used to pinpoint problems in controller and remaining components of cooling fan system.

COOLING FAN (ESCORT WITH A/C)

1. Check 15-amp fuse (F-17) in fuse panel for the A/C. Check Dark Blue fusible link to cooling fan controller. Replace as necessary. If okay, determine when cooling fan does or does not operate. If fan operates during A/C operation only, proceed to step 2). If it does not operate during A/C operation or during high engine coolant temperatures, proceed to step 10. If it operates during high coolant temperatures only, proceed to step 5).
2. Disconnect cooling fan temperature switch connector. Switch is located on upper left-hand side of engine, near the distributor. Install jumper wire between connector terminals. If cooling fan motor operates, replace cooling fan temperature switch. If fan does not operate, proceed to next step.
3. Verify cooling fan temperature switch ground. Ensure coolant temperature is greater than 221°F (105°C). Check for continuity between Brown/White wire at cooling fan temperature switch and ground. If no continuity exists, repair ground circuit. SeeFig. (Scheme 3).
4. With engine coolant temperature at 221°F (105°C), shut engine off. Remove connector from cooling fan temperature switch. Check for battery voltage at Tan/Orange wire of connector. If no voltage exists, repair open circuit. (Scheme 3)
5. Check cooling fan controller system ground at terminal No. 5 (Black wire) of cooling fan controller. Cooling fan controller is located under right side of instrument panel, in front of evaporator mounting bracket. If ground is okay, proceed to next step. If not, repair ground circuit.
6. Remove connector from cooling fan controller. Turn ignition on. Check for voltage at Tan/Yellow, Light Green/Purple and Gray/Yellow wires with mode switch in "A/C" or "DEFROST" position. If voltage exists, replace cooling fan controller. If no voltage at one or more circuits exists, proceed to next step.
7. Remove connector from clutch cycling pressure switch and install a jumper wire between connector terminals. Switch is located on top of accumulator for A/C system. If cooling fan operates, proceed to next step. If not, proceed to step 9).
8. Check A/C system for refrigerant charge pressure of 50 psi (3.5 kg/cm 2 ) with ambient temperature of approximately 50°F (10°C). If no refrigerant pressure exists, leak test, service and recharge system. If refrigerant pressure is above 50 psi, replace clutch cycling pressure switch.
9. Remove connector from A/C button assembly on the dash. Install jumper wire between Light Green/Purple and White/Light Blue wires. Check for voltage at Tan/Yellow wire at cooling fan controller. (Scheme 3) If voltage exists, replace A/C button switch and return to step 6). If no voltage exists, repair open wiring circuits.
10. Disconnect connector at cooling fan. Connect jumper wires from positive battery lead to Brown/Yellow wire and negative lead to Black wire. If cooling fan operates, proceed to next step. If not, replace cooling fan.
11. Remove jumper wires and reconnect connector to cooling fan. Disconnect connector from cooling fan controller. Turn ignition on. Check for voltage at Gray/Yellow, Tan/Orange, Tan/Yellow and Light Green/Purple wires. Check for good ground at Black wire of cooling fan controller. If voltage and grounds are okay, proceed to next step. If not, repair circuits as necessary.
12. Apply battery voltage at Brown/Yellow wire of cooling fan relay. This will by-pass the relay contacts. Cooling fan relay is located on left front corner of engine compartment near the headlight. If cooling fan operates, proceed to step 14).
13. If cooling fan does not operate, check continuity of wiring circuit between cooling fan relay and cooling fan. If wiring is okay, check operation of cooling fan. If wiring is open or shorted, repair wiring circuit.
14. If cooling fan operated in step 12), remove connector from cooling fan temperature switch. Ensure continuity exists between Brown/White or Black wire of connector and ground. If not, repair as necessary. Install jumper wire across connector terminals. Check that ground exists in Tan/Orange wire to cooling fan controller. If not, repair as necessary. Replace cooling fan relay if all ground circuits are okay.

COOLING FAN (ESCORT W/OUT A/C)

1. Disconnect cooling fan connector. Install a jumper wire between Black wire and body ground. Apply battery voltage to Brown/Yellow wire. If cooling fan does not operate, replace cooling fan. If cooling fan operates, reconnect cooling fan connector and proceed to next step.
2. Disconnect electrical connector at cooling fan temperature switch. Cooling fan temperature switch is located in thermostat housing. With ignition off, check for battery voltage at Tan/Orange wire. (Scheme 4) If voltage exists, proceed to next step. If no voltage exists, check for an open or short in Tan/Orange wire circuit or circuit breaker. Repair as necessary and recheck operation.
3. Install jumper wire between terminals of cooling fan temperature switch connector. With ignition off, cooling fan should run. If fan operates, replace cooling fan temperature switch and recheck operation. If not, leave jumper wire intact and proceed to next step.
4. Disconnect cooling fan connector. With ignition off, check for battery voltage at Brown/Yellow wire of connector. If battery voltage exists, proceed to next step. If voltage does not exist, check for open in wiring between cooling fan temperature switch and cooling fan connector. Repair or replace as necessary and recheck operation.
5. Check for continuity at ground circuit (Black wire) between cooling fan and the body ground. If continuity exists, replace cooling fan. Install cooling fan temperature switch connector and recheck. If no continuity exists, repair open in the ground circuit. Connect cooling fan connector and temperature switch connector and recheck operation.

COOLING FAN (TEMPO & TOPAZ WITH A/C)

1. Ensure all fuses are okay. Check Black fusible link to cooling fan relay and Blue fusible link to cooling fan controller. Replace as necessary. If okay, determine when cooling fan does or does not operate. If it operates during A/C operation only, proceed to step 2). If cooling fan does not operate during A/C operation or during high engine coolant temperatures, proceed to step 11). If it operates during high coolant temperatures only, proceed to step 5).
2. Ensure "A/C" and "DEFROST" are off. Disconnect cooling fan temperature switch connector. Switch is located on upper left-hand side of engine, near the ignition coil. Install jumper wire between Tan/Orange wire and ground. (Scheme 5) Turn ignition on. If cooling fan operates, proceed to next step. If cooling fan did not operate, proceed to step 4).
3. Ensure continuity exists in Brown/White wire to ground. If not, repair open circuit. With engine coolant temperature greater than 210°F (85°C), continuity should exist between terminals and cooling fan should operate. Replace cooling fan temperature switch if cooling fan operates.
4. Remove connector from cooling fan controller. Cooling fan controller is mounted on right cowl panel, under instrument panel and can be serviced through glove compartment opening. Check for continuity of Tan/Orange wire from controller to the cooling fan temperature switch. If continuity exists, replace cooling fan controller. If no continuity exists, repair open circuit.
5. Check that continuity exists from Black wire from cooling fan controller to ground. Repair circuit if no continuity exists. If ground circuit is okay, proceed to next step.
6. Remove connector from cooling fan controller. Check that voltage exists at Tan/Yellow and Light Green/Purple wires. If voltage exists, replace cooling fan controller. If no voltage exists, proceed to next step.
7. Remove connector from clutch cycling pressure switch and install a jumper wire between connector terminals. Switch is located on top of accumulator for A/C system. If cooling fan operates, proceed to next step. If not, proceed to step 9).
8. Check A/C system for refrigerant charge pressure of 50 psi (3.5 kg/cm 2 ) with ambient temperature of approximately 50°F (10°C). If no refrigerant pressure exists, leak test, service and recharge system. If refrigerant pressure is above 50 psi (3.5 kg/cm 2 ), replace clutch cycling pressure switch.
9. Remove connector from A/C push button on dash assembly. Check for voltage at Light Green/Purple and White/Light Blue wires. If voltage exists, replace A/C button switch and proceed to next step. If no voltage exists, repair open wiring circuits.
10. Remove connector from clutch cycling pressure switch and install a jumper wire between connector terminals. Switch is located on top of accumulator for A/C system. If cooling fan operates, proceed to next step. If not, check for open or shorted circuit in Light Green/Purple and Tan/Yellow wires between cooling fan controller and clutch cycling pressure switch.
11. Remove connector from cooling fan. Apply battery voltage to Brown/Yellow wire and ground the Black wire. If cooling fan operates, proceed to next step. Replace cooling fan if it fails to operate.
12. Install connector on cooling fan. Remove connector from cooling fan controller. With ignition on, check for voltage at Gray/Yellow, Tan/Yellow and Light Green/Purple wires. Check that continuity exists between Black wire and ground. Repair if necessary. If all circuits are okay, proceed to next step.
13. Apply battery voltage at Brown/Yellow wire of cooling fan controller. If cooling fan operates, replace cooling fan controller.
14. If cooling fan failed to operate, remove connector from cooling fan relay. Apply battery voltage at Brown/Yellow wire of cooling fan relay which goes to the cooling fan. This by-passes contacts of the relay. If cooling fan operates, proceed to next step. If cooling fan does not operate, check cooling fan ground circuit and cooling fan operation.
15. Ensure battery voltage exists at Yellow wire of cooling fan relay. Ensure continuity exists between Black wire at cooling fan relay and ground. Install connector on cooling fan relay. Apply battery voltage at Brown/Yellow wire of cooling fan relay. If fan does not operate, replace cooling fan relay.

COOLING FAN (TEMPO & TOPAZ W/OUT A/C)

1. Disconnect cooling fan connector. Install jumper wire between Black wire and body ground. Apply battery voltage to Brown/Yellow wire. If cooling fan does not operate, replace cooling fan. If cooling fan operates, reconnect cooling fan connector and proceed to next step.
2. Disconnect electrical connector at cooling fan temperature switch. Cooling fan temperature switch is located in thermostat housing. With ignition on, check for battery voltage at Tan/Orange wire of connector. (Scheme 6) If voltage exists, proceed to next step. If no voltage exists, check for an open or short in Tan/Orange wire circuit or fusible link. Repair as necessary and recheck operation.
3. Install jumper wire between terminals of cooling fan temperature switch connector. With ignition on, cooling fan should operate. If fan operates, replace cooling fan temperature switch and recheck operation. If not, leave jumper wire connected and proceed to next step.
4. Disconnect electrical connector at cooling fan relay. Relay is located on left radiator support, near the headlight. Check for voltage at Brown/White wire and Yellow wire of connector. If voltage does not exist, repair open or short in wiring circuits.
5. If voltage exists, install connector at cooling fan relay. Ensure continuity exists at ground circuit (Black wire) for cooling fan relay. Repair circuit if necessary. Install jumper wire between Yellow wire and Brown/Yellow wire terminals. If cooling fan operates, replace the relay.
6. If cooling fan did not operate in step 5), disconnect cooling fan connector. With ignition on and jumper wire installed on cooling fan temperature switch, check for battery voltage at Brown/Yellow wire to cooling fan. If battery voltage exists, proceed to next step. If voltage did not exist, check Brown/Yellow wiring circuit for an open or short. Repair as necessary and recheck operation.
7. Check for continuity at Black wire and ground at cooling fan. If continuity exists, replace cooling fan motor, connect cooling fan temperature switch connector and recheck operation. If no continuity exists, repair open ground circuit. Connect cooling fan motor connector and temperature switch connector and recheck operation.

Condition & Cause

Incorrect cooling or other air conditioning electrical system malfunctions may not be alleviated by replacing the A/C fan controller.

Diagnosis Procedure

Use the following fan controller and A/C electrical system diagnostic chart and the appropriate Chassis Wiring Diagram in the WIRING DIAGRAM Section to resolve an inoperative A/C cooling fan concern before replacing the A/C fan controller.

Note. The replacement parts have internal circuit protection. When the new controllers are used to service these vehicles, terminals #2 and #4 are not used.

Keep the following points in mind when checking the A/C ckts

Scheme 3

1. For A/C operation, voltage must be available at fan controller pin #3.
2. The A/C clutch coil current must not exceed 6 amps.
3. Use a jumper wire to supply the proper voltage or ground to check fault or proper operation of the cooling fan A/C system if voltage or ground is not available at the controller.
4. Check for voltage at the controller with: the connector plugged into the controller. the key in the "RUN" position, except where an exception is noted.
5. Check for the following items at the cooling fan, coolant switch splices and connector/terminals if there is intermittent A/C operation: breaks poor crimps loose terminals.

Electric Cooling Fan Wiring Diagram Escort (With A/C). Scheme 4

Electric Cooling Fan Wiring Diagram Escort (Without A/C). Scheme 5

Electric Cooling Fan Wiring Diagram Tempo & Topaz (With A/C). Scheme 6

Electric Cooling Fan Wiring Diagram Tempo & Topaz (W/out A/C). Scheme 7

See also:
• WIRING DIAGRAM