Engine Cooling Fan Ford Taurus I

DESCRIPTION

The basic liquid cooling system consists of a radiator, water pump, thermostat, cooling fan, pressure cap, heater (if equipped), various connecting hoses and cooling passages in the block and cylinder head. In addition, many cars use a fan clutch (incorporating a thermostatic control) or flexible fan blade. These reduce noise and power requirements at higher engine speeds.

Some models may use a thermostatic vacuum switch to advance ignition timing in the event of overheating. Most models use a coolant recovery system to prevent loss of anti-freeze.

DRAINING

Remove radiator cap and open heater control valve to maximum heat position. Open drain cocks or remove plugs in bottom of radiator and in engine block. In-line engines usually have one plug or cock, while "V" type engines will have two, one in each bank of cylinders.

CLEANING

A good cleaning compound removes most rust and scale. Follow manufacturer's instructions in the use of the cleaner. If considerable rust and scale has to be removed, flushing should be used. Clean radiator air passages by blowing with compressed air from back to front of radiator.

FLUSHING

1. Back flushing is a very effective means of removing rust and scale from a cooling system. For best results, the radiator, engine and heater core should be flushed separately.
2. To flush radiator, connect flushing gun to water outlet of radiator and disconnect water inlet hose. Use a leadaway hose, connected to radiator inlet, to prevent flooding the engine. Use air in short bursts only as a clogged radiator could be easily damaged. Continue flushing until water runs clear.
3. To flush engine, first remove thermostat and replace housing. Connect flushing gun to water outlet of engine. Disconnect heater hoses from engine. Flush using short air bursts until water runs clean. Flush heater core as described for radiator. Make sure heater valve is set to maximum heat position before flushing heater.

REFILLING

Engine should be running while refilling cooling system to prevent air from being trapped in the engine block. After system is full, continue running engine until thermostat is open, then recheck fill level. Do not overfill system. Refer to appropriate article for correct cooling system capacity.

Scheme 1

1. Visually inspect thermostat for corrosion and proper sealing of valve and seat. If satisfactory, suspend thermostat and a thermometer in a container with a 50/50 mixture of anti-freeze and water (AMC recommends 100% anti-freeze). (Scheme 1)
2. Do not allow either thermostat or thermometer to touch bottom of container as this concentration of heat could cause an incorrect reading. Heat water until thermostat just begins to open. (Scheme 1): Testing Thermostat in Anti-Freeze/Water Solution NOTE: Support thermometer so it does not touch bottom of container.
3. Read temperature on thermometer. This is the initial opening temperature and should be within specifications. Continue heating water until thermostat is fully open and note temperature. This is the fully opened temperature. If either reading is outside of specifications, Replace thermostat, as it is not adjustable.

PRESSURE TESTING RADIATOR CAP

A pressure testing tool is used to test both radiator cap and complete cooling system. Test as follows, following tool manufacturer's instructions.

Visually inspect radiator cap, then dip cap in water and connect to tester. Pump tester to bring pressure to upper limit of cap specifications. If cap fails to hold pressure within specifications, replace cap.

Scheme 2

1. With engine off, wipe radiator filler neck seat clean. Fill radiator to correct level. Attach tester to radiator and pump until pressure is at upper limit of radiator rating.
2. If pressure drops, inspect for external leaks. If no leaks are apparent, detach tester and run engine until normal operating temperature is obtained. Reattach tester and observe. If pressure builds up immediately, a possible leak exists from a faulty head gasket or crack in head or block. CAUTION: Pressure may build up quickly. Release any excess pressure or cooling system damage may result.
3. If there is no immediate pressure build up, pump tester to within system pressure range (on radiator cap). Vibration of gauge pointer indicates compression or combustion leak into cooling system. Isolate leak by shorting each spark plug wire to cylinder block. Gauge pointer should stop or decrease vibration when leaking cylinder is shorted. CAUTION: Do not disconnect spark plug wires while engine is operating, or operate engine with spark plug shorted for more than 1 minute as catalytic converter may be damaged.
4. Remove engine and transmission (automatic only) oil dipsticks and check if water drops appear in oil. If so, a serious internal leak is indicated. If all checks are negative and system holds pressure for 2 minutes, there are no serious leaks in system. (Scheme 2): Pressure Testing Cooling System NOTE: Pump up to specified pressure.

ANTI-FREEZE CONCENTRATION

Note. On models using aluminum engines or cooling system components, refer to Owners Manual for anti-freeze requirements and recommendations. Aluminum components require a different formulation of anti-freeze to prevent corrosion.

On all cooling systems, test anti-freeze concentration using anti-freeze tester. Tester should have a temperature-compensating feature, as failing to take temperature into consideration could cause an error as large as 30°F. Follow tester manufacturer's instructions for correct use of tester.

A coolant recovery system differs from other cooling systems in that an overflow bottle is connected to the radiator overflow hose. The overflow bottle is transparent or translucent to permit checking of coolant level without removing radiator cap. No adjustment or test is required except keeping vent hole or hose clean and checking pressure relief of radiator cap.

OPERATION

As coolant temperature rises and pressure in system exceeds pressure relief valve of radiator cap, excess coolant flows into overflow bottle. As engine cools and coolant contracts, a vacuum is formed in the system. The vacuum draws coolant, stored in overflow bottle, back into radiator. In a properly maintained cooling system, the only coolant losses will be through evaporation.

Typical Coolant Recover System. Scheme 3

Note. Overflow bottle captures and releases coolant according to temperature.

THERMOSTATICALLY CONTROLLED ELECTRIC COOLING FANS

ELECTRIC COOLING FAN APPLICATIONS

The electro-drive cooling fan system consists of a 2-speed fan on all 2.5L, 3.0L and 3.8L engines with automatic transmission or a one-speed fan on 2.5L engines with manual transmission. The electric motor is attached to the fan shroud located behind the radiator. The electro-drive cooling fan is wired to operate only when the ignition switch is in the "RUN" position, thereby preventing cooling fan operation after the ignition switch is turned to the "OFF" position.

The cooling fan is controlled during vehicle operation by the integrated relay control assembly and EEC-IV module. The cooling fan will energize under the following conditions

1. Engine temperature is higher than normal. Fan comes on at 215°F (102°C), and goes off at 210°F (99°C).
2. A/C is on and vehicle speed does not provide enough natural air flow. Fan comes on at speeds at or below 43 MPH and goes off at 48 MPH. Low speed cooling fan motor operation is achieved by using a dropping resistor in series with the motor.
3. Cooling fan is turned on high if engine temperature is higher than desirable and fan has been operating at a low speed. Fan comes on at 230°F (110°C), and goes off at 224°F (107°C).
4. Cooling fan will turn off (providing engine coolant temperature is not too high) if driver demand is Wide Open Throttle (WOT) or A/C clutch is not cycling rapidly. Several different controllers are available depending on application. Proper operation of the system cannot be obtained unless the correct controller is used.

COOLING FAN SYSTEM DIAGNOSIS WITH A/C

Note. Once cooling fan controller pin voltage/continuity tests are performed and the controller is determined to be not at fault, refer to this section for diagnosis information. These procedures can be used to pinpoint problems in the controller and remaining components of the cooling fan system.

A/C Integrated Relay Controller

The Integrated Relay Controller Module (IRCM) interfaces with the EEC-IV system to provide control of the cooling fan, A/C clutch, and fuel pump. The module incorporates the ECC power relay which supplies current to the EEC-IV system.

The location of the IRCM is on the radiator support bracket. The operating voltage of the IRCM is between 7 and 17 volts.

For diagnostic information concerning A/C components controlled the IRCM and/or for the IRCM itself, see the following A/C INTEGRATED RELAY CONTROLLER trouble shooting charts.

PLEASE READ THIS BEFORE PERFORMING THE FOLLOWING TESTS

Note. In an effort to make the titles display all of the necessary information while viewing the SUBJECT menu, we have implemented some abbreviations. In the following subject titles, Integrated Controller is referred to as IC wherever necessary to fit all critical information on one line.

X1 CHECK BATTERY VOLTAGE

X2 CHECK BATTERY GROUND

X3 GROUND FAULTY ISOLATION

X4 PROCESSOR GROUND FAULT ISOLATION

X5 CHECK CONTINUITY OF SIGNAL RETURN CIRCUIT

X6 MEASURE VOLTAGE & GROUND TO INTEGRATED CONTROLLER (IC)

X7 KEY POWER TO INTEGRATED CONTROLLER (IC)

X8 MEASURE CONTINUITY OF VPWR

X9 MEASURE CONTINUITY OF POWER GROUND TO INTEGRATED CONTROLLER (IC)

X10 CODE 72 OR 78: INTERMITTENT OPEN IN VPWR CIRCUIT

X11 CHECK POWER-TO-PUMP(S) CIRCUIT

X12 CHECK RESISTANCE OF FUEL PUMP INERTIA SWITCH

X13 POWER-TO-PUMP(S) CIRCUIT CONTINUITY CHECK

X14 CHECK POWER-TO-PUMP(S) FOR SHORT TO POWER

X15 SERVICE CODE: 87 CHECK CONTINUITY OF FUEL PUMP CIRCUIT

X16 CHECK FUEL PUMP CIRCUIT FOR SHORTS TO POWER & GROUND

X17 CHECK RESISTANCE OF FUEL PUMP RELAY COIL

X20 NO FAN, HIGH OR LOW W/NO CODE 83

X21 CHECK FAN MOTOR

X22 CHECK FAN RUNNING MODE (LOW)

X23 MEASURE BATTERY VOLTAGE SUPPLY AT FAN - BYPASSING IC

X24 COOLING FAN GROUND VERIFICATION

X25 JUMPER HIGH ELECTRIC-DRIVE SIGNAL (HEDF) TO GROUND

X26 CHECK ECT SENSOR

X30 SERVICE CODE 83: CHECK RESISTANCE OF HEDF CONTROLLER CIRCUIT

X31 CHECK HEDF PROCESSOR SIGNAL TO INTEGRATED CONTROLLER FOR AN OPEN

X32 CHECK FOR SHORTS TO GROUND IN THE HEDF CIRCUIT

X33 CHECK FOR SHORTS TO POWER IN THE HEDF CIRCUIT

X35 LOW OR HIGH SPEED FAN ALWAYS "ON", NO SERVICE CODE 83 OR 67

X36 CHECK EDF CIRCUIT FOR SHORTS TO POWER

X37 CHECK EDF FOR SHORT TO GROUND

X40 NO FAN

X41 CHECK FAN MOTOR

X42 CHECK FAN RUNNING MODE

X43 MEASURE BATTERY VOLTAGE SUPPLY AT FAN - BYPASSING IC

X44 CHECK EDF CIRCUIT FOR SHORT TO GROUND

X45 COOLING FAN GROUND VERIFICATION

X46 ECT SENSOR CHECK

X50 CHECK FOR VOLTAGE AT A/C CLUTCH

X51 CHECK FOR CONTINUITY FROM INTEGRATED CONTROLLER TO A/C CLUTCH

X52 ENTER OUTPUT STATE CHECK

X53 CHECK WAC OUTPUT FOR PROPER ELECTRICAL OPERATION

X54 CHECK FOR VOLTAGE AT A/C CLUTCH SWITCH

X55 CHECK CONTINUITY OF ACCS TO INTEGRATED CONTROLLER (IC)

X56 CHECK CONTINUITY OF ACCS CIRCUIT

X57 CHECK CONTINUITY IN WAC TO INTEGRATED CONTROLLER (IC) CIRCUIT

X58 CHECK WAC CIRCUIT FOR SHORTS TO GROUND

X59 CHECK WAC CIRCUIT FOR SHORTS TO POWER

X60 CHECK FOR VOLTAGE AT A/C CLUTCH

X61 CHECK FOR VOLTAGE AT A/C INPUT TO CONTROLLER

X70 NO FAN PRIMARY OR SECONDARY W/NO CODE 82 OR 88

X71 FAN MOTORS CHECK

X72 CHECK FAN RUNNING MODE (LOW)

X73 MEASURE BATTERY VOLTAGE SUPPLY AT FANS - BYPASSING IC

X74 COOLING FAN GROUND VERIFICATION

X75 JUMPER SECONDARY ELECTRIC DRIVE SIGNAL (HEDF) TO GROUND

X76 ECT SENSOR CHECK

X80 SERVICE CODE 82 OR 88: CHECK EDF PROCESSOR SIGNAL TO

X81 CHECK FAN RUNNING MODE

X82 FAN ALWAYS ON W/CODE 82 OR 88: CHECK EDF SIGNAL TO IC FOR OPEN CKT

X83 CHECK EDF CIRCUIT FOR SHORTS TO POWER

X84 CHECK EDF SHORT TO GROUND

X90 SERVICE CODE 95: CHECK INERTIA SWITCH

X91 VERIFY THAT FUEL PUMP IS OFF

X92 CHECK FOR FUEL PUMP RELAY ALWAYS CLOSED

X93 CHECK CONTINUITY OF FPM CIRCUIT

X94 CHECK FOR CONTINUITY BETWEEN FPM CIRCUIT & GROUND

X95 SERVICE CODE 96: CHECK CONTINUITY OF POWER-TO-PUMP CIRCUIT

X96 VERIFY FUEL PUMP OPERATION

X100 CONTINUOUS MEMORY CODE 95: CHECK EEC-IV HARNESS

X101 CHECK FPM CIRCUIT

X102 CONTINUOUS MEMORY CODE 96 CHECK FOR CONTINUOUS MEMORY CODE 87

X103 CHECK EEC-IV HARNESS

X104 CONTINUOUS MEMORY SERVICE CODE 87: CHECK EEC-IV HARNESS

This unit is a fixed blade assembly designed to flex the blades as the engine RPM increases. As RPM increases blade pitch decreases, thereby saving power and decreasing noise level. No adjustment or test is required beyond keeping the fan belt adjusted to the proper tension.

Flex Blade Fan Assembly. Scheme 4

Most air conditioned models use a thermostatically controlled fluid fan and torque control clutch. The thermal control drive is a silicone-filled coupling connecting the fan to the fan pulley, and is operated by a control valve. Control valve is operated by a temperature sensitive bimetal coil or strip and controls the flow of silicone through the clutch.

During periods of operation when radiator discharge air temperature is low, the fan clutch limits the fan speed. High radiator discharge air temperature causes bimetal to allow a greater flow of silicone to enter the clutch. This increases the drag between the driven member and driving member resulting in a higher fan speed and increased cooling.

TESTING

Note. It will take approximately 5 to 10 minutes for the temperature to become high enough to allow engagement of the fan clutch. While operating engine under these conditions, observe temperature light to prevent overheating. If hot light comes on, remove cover from radiator grille.

In cases of engine overheating or insufficient air conditioning proceed with the following tests

Scheme 5

1. Start with a cool engine to ensure complete fan clutch disengagement.
2. Cover radiator grille sufficiently to induce high engine temperature.
3. Start engine and operate at 2000 RPM. Turn on air conditioning if equipped.
4. A fan roar will be noticed when the fan clutch engages.
5. As soon as the clutch engages, remove the radiator grille cover and turn the A/C off to assist in engine cooling.
6. After several minutes the fan clutch should disengage. This can be determined by a reduction in fan speed and roar. If the fan fails to function as described, it should be replaced. (Scheme 5): Thermostatically Controlled Fan Assembly - Shown With Stamped Face & Bi-Metal Coil Spring

Electric Cooling Fan 2.5L CFI Manual Transaxle. Scheme 6

Electric Cooling Fan 2.5L CFI & 3.0L EFI Automatic Transaxle W/OD. Scheme 7

Tempo & Topaz Without A/C Electric Cooling Fan. Scheme 8

Tempo & Topaz With A/C Electric Cooling Fan. Scheme 9