Engine Cooling Fan Ford Probe I

DESCRIPTION

On the 2.2L models with M/T, a single-speed electric fan is used. A cooling fan relay and coolant temperature switch are used for fan operation. On 2.2L models with A/T, a 2-speed cooling fan is used. Cooling fan relay and high speed fan relay are used to obtain the variable fan speeds. On 3.0L models, cooling fan operation is controlled by the EEC and Integrated Relay Controller Module (IRCM).

OPERATION

2.2L MODELS WITH M/T

Cooling fan relay is controlled by the coolant temperature switch. When coolant temperature exceeds 206°F (97°C), coolant temperature switch contacts close. This closes the cooling fan relay and this provides cooling fan operation. When A/C is operating under full throttle, the Wide Open Throttle A/C Cutoff Relay (WAC) controls cooling fan relay and operates cooling fan. Cooling fan relay is located on main relay box.

2.2L MODELS WITH A/T

A 2-speed cooling fan is used. Cooling fan relay and high speed fan relay are used to obtain the variable fan speeds. Low speed is obtained when coolant temperature exceeds 206°F (97°C), coolant temperature switch contacts close. High speed is obtained when coolant temperature exceeds approximately 230°F (110°C) and High Speed Fan Switch (HSFS) closes. This closes the high speed fan relay and increases fan speed. Cooling fan operates on high speed whenever A/C compressor is operating. Two different electrical signals (one for low speed and one for high speed) are sent to EEC for maintaining idle speed control. Fan speed variation is obtained by usage of resistor, located between cooling fan relay and the fan motor. Resistor is located next to cooling fan near fan shroud. Relays are located on main relay box near firewall. (Scheme 1)

3.0L MODELS

Cooling fan operation is controlled by the EEC and Integrated Relay Controller Module (IRCM). The IRCM is part of Ford's Electronic Engine Control (EEC-IV) system. No other operating information available from manufacturer.

TROUBLE SHOOTING

Note. Ensure 40-amp cooling fan fuse is okay prior to checking system. Fuse is in the main fuse block, located in left front corner of engine compartment, near battery.

Scheme 1

1. With engine cold, disconnect cooling fan temperature switch connector. Coolant temperature switch is located in the radiator. Turn ignition on. Using jumper wire, connect Black/Green wire of connector to ground. If cooling fan operates, replace cooling fan temperature switch. If cooling fan does not operate, proceed to next step.
2. With engine cold, connect jumper wire to Black/Green terminal of cooling fan relay. Cooling fan relay is located in main relay box near the firewall. (Scheme 1) Connect jumper wire to ground and turn ignition on. If cooling fan operates, repair open circuit in Black/Green wire from cooling fan relay to the cooling fan temperature switch. (Scheme 2)and (Scheme 3). If cooling fan did not operate, proceed to next step.
3. Turn ignition on. Measure voltage at Black/Red and Black/White terminals of cooling fan relay. Voltage readings should be at least 10 volts. If voltage is correct, proceed to next step. If voltage readings are low, check for open or short in wiring circuit.
4. Turn ignition on. Measure voltage at Black/White wire of cooling fan relay. Ground Black/Green wire at cooling fan relay and recheck voltage. Voltage should be greater than 10 volts with Black/Green wire grounded and less than one volt without wire grounded. If voltage is correct, proceed to next step. If voltage is not correct, replace cooling fan relay.
5. Disconnect cooling fan connector. Turn ignition on. Using jumper wire, apply battery voltage to Blue/White wire (M/T models) or Blue/Black wire (A/T models) to cooling fan motor. If cooling fan did not operate, check ground circuit at cooling fan. Replace cooling fan if ground circuit is okay. On A/T models if cooling fan operates, proceed to next step. On M/T models if cooling fan operates, check Blue/White wire from cooling fan relay to cooling fan for open or short and proceed to step 12).
6. On A/T models, connect jumper wire from Black/Green wire of cooling fan temperature switch to ground. Disconnect resistor. Install jumper wire between Black/White and Blue/Black wires for resistor. Turn ignition on. If cooling fan operates, replace resistor. If cooling fan does not operate, check for open wire to resistor and cooling fan.
7. On A/T models, disconnect high speed fan switch. Using jumper wire, ground Light Blue/Red wire terminal of high speed fan switch connector. Turn ignition on. If cooling fan operates, replace high speed fan switch. If cooling fan does not operate, proceed to next step.
8. On A/T models, ground Light Blue/Red terminal of high speed fan relay. Turn ignition on. If cooling fan operates, check for open in Light Blue/Red wire. If cooling fan does not operate, proceed to next step.
9. With ignition on, check voltage at Black/White and Black/Red wire terminals of high speed fan relay. Voltage should be at least 10 volts. If voltage is okay, proceed to next step. If voltage is not correct, repair open or shorted wire.
10. Turn ignition on. Check voltage at Blue/Black terminal of high speed fan relay. Ground Light Blue/Red terminal and note voltage. Voltage should exceed 10 volts with Light Blue/Red wire grounded and no voltage should exist with wire not grounded. If voltage is correct, proceed to next step. If voltage is not correct, replace high speed fan relay.
11. With ignition off, disconnect resistor. Measure resistance across Blue/White and Blue/Black wires. Resistance should be 100-10,000 ohms. If resistance is not correct, replace resistor. If resistance is within specification, check Blue/Black wire from high speed fan relay to cooling fan motor.
12. On all models, ensure engine is cold and ignition is on. Disconnect cooling fan temperature switch connector. If cooling fan stops, replace cooling fan temperature switch. If cooling fan continues to operate, proceed to next step.
13. With engine cold and ignition on, disconnect ECA 60-pin connector, located in center console. If cooling fan does not stop, proceed to next step. If cooling fan stops on A/T models, check for defective Black/Green wire from cooling fan relay to ECA or Blue/Red wire from high speed fan relay and WAC relay to ECA. If cooling fan stops on M/T models, check for defective Black/Green wire from cooling fan relay and WAC relay to ECA.
14. With ignition off, disconnect cooling fan relay, ECA and cooling fan temperature switch. Using ohmmeter, measure resistance between Black/Green wire terminal of cooling fan relay and ground. If resistance exceeds 10,000 ohms, reconnect cooling fan temperature switch and cooling fan relay and proceed to next step. If resistance is less than 10,000 ohms, check for short in Black/Green wire.
15. With ignition on, engine cold, disconnect ECA and cooling fan relay. If cooling fan stops, replace cooling fan relay. On A/T models if cooling fan did not stop, proceed to next step. On M/T models if cooling fan did not stop, check Black/White wire from cooling fan relay to cooling fan for short to power source. Replace cooling fan if wiring is okay.
16. On A/T models, turn ignition on. With engine cold, disconnect high speed fan switch. If cooling fan stops, replace high speed fan switch. If fan did not stop, proceed to next step.
17. Turn ignition off. Disconnect ECA, high speed fan switch and high speed fan relay. Measure resistance between Blue/Red wire of high speed relay terminal and ground. If resistance exceeds 10,000 ohms, proceed to next step. If resistance does not exceed 10,000 ohms, check Blue/Red wire circuit. If wiring is okay, pinpoint test at ECA must be performed for the high speed fan.
18. With ignition on and engine cold, disconnect high speed fan relay. If cooling fan stops, replace high speed fan relay. If cooling fan did not stop, check Blue/Black wire from high speed fan relay to cooling fan for short to power source. If wiring is okay, replace cooling fan.

Scheme 2

Scheme 3