Testing & Adjusting

Usage:

Troubleshooting (6I4427 Fan Clutch, 123-6968 Fan Clutch And 136-7609 Fan Clutch)

This troubleshooting guide can be an aid for the service personnel to find the cause of existing problems with the fan clutch. Several common problems are covered in the guide.

Identify your particular type of problem from the Troubleshooting Problem List, then go directly to that problem in the guide. However, when you begin the procedure for that problem, start at Step 1 and follow through the step by step procedure. The steps that follow in a particular problem provide a definite sequence to be followed for a logical, one by one elimination of many variables. These steps are arranged in order from the more probable/easiest to check, to the less probable/more complex to check.

Whenever the cause of the problem is found and corrected, stop the test (as shown by STOP). Do not continue through the complete procedure just because it is there. Verify the repair has eliminated the problem.

Troubleshooting Problem List

Fan Does Not Lock Up, Fan Runs Slowly 17

Fan Runs Continuously 17

Oil Leakage At The Rear Face Of The Fan Clutch 19

Troubleshooting Flow Chart For ECM Controlled Fan Clutches (123-6968 and 136-7609) If Engine Runs Hot Or Overheats 16

Troubleshooting Flow Chart For ECM Controlled Fan Clutches (123-6968 And 136-7609) If Engine Runs Hot Or Overheats

Fan Does Not Lock Up, Fan Runs Slowly

Probable Cause(s):

* Defective Coolant Sensor

* Oil Flow Restriction And/Or Defective Solenoid Valve

* Defective Or Worn Out Clutch Plates

1. Defective Coolant Sensor

1: Check The Electrical System Of The Fan Clutch Control System

a. Disconnect the fuse for the control system with the engine running.

Expected Result: The fan clutch is fully engaged.

Result(s):

The fan clutch is fully engaged.

Replace the coolant sensor. STOP.

The fan clutch is not fully engaged.

Continue troubleshooting Probable Cause:

Defective Fan Clutch Solenoid Valve.

2. Oil Flow Restriction And/Or Defective Solenoid Valve

1: Check Engine Oil Pressure

a. Check engine oil pressure supply to the control valve at the engine port.

Expected Result: The engine oil pressure is normal.

Result(s):

Engine oil pressure is normal.

Continue to Step 2.

The clutch should be fully engaged when 276 kpa (40 psi) oil pressure is supplied at the control pressure port.

The clutch should fully disengage and run at 50 to 300 rpm when less than 14 kpa (2 psi) oil pressure is supplied at the control pressure port.

Engine oil pressure is low.

Refer to Troubleshooting in the Engine Service Manual.

2: Check Lines To And From Control Valve

a. Disconnect the inlet and outlet lines at the control valve and connect them together to bypass the valve.

Expected Result: The fan clutch is fully engaged.

Result(s):

The fan clutch is fully engaged.

Replace the fan clutch solenoid valve. STOP.

The fan clutch is not fully engaged.

Continue troubleshooting Probable Cause:

Replace lines and check to see if the fan operates properly. If the fan still does not operate properly, replace the clutch.

Fan Runs Continuously

Probable Cause(s):

* Defective Fan Clutch Solenoid Valve

* Defective Connectors And/Or Wires

* Defective Air Conditioner Switch

* Defective Aftercooler Switch

* Defective Brake Oil Switch

* Defective Coolant Sensor

1. Defective Fan Clutch Solenoid Valve.

1: Check The Fuse For The Fan Clutch Control System

a. Turn the engine OFF.

b. Inspect the fuse.

Expected Result: The fuse is not blown.

Result(s):

The fuse is not blown.

Proceed to next step.

The fuse is blown.

Replace the fuse. STOP.

2: Check For Fan Clutch Solenoid Valve Supplied Voltage

a. Turn ignition key ON, engine OFF.

b. Use the 6V7070 Digital Multimeter on the DC setting and 7X1708, 7X1709 Knife Connectors to measure the voltage from pin-1 to pin-2.

Expected Result: The fan clutch solenoid valve supplied voltage is 24 VDC.

Result(s):

The fan clutch solenoid valve supplied voltage is 24 VDC.

Replace the fan clutch solenoid valve.

The fan clutch solenoid valve supplied voltage is not 24 VDC.

Continue troubleshooting Probable Cause:

Defective Connectors And/Or Wires

2. Defective Connectors And/Or Wires

1: Check Electrical Connectors And Wiring

a. Ensure the connectors are properly locked (clicked) together and the two halves cannot be pulled apart.

b. Inspect Packard Connectors, make sure the sensor is latched on both sides.

Expected Result: Connector is not cracked or broken or the connector will not lock.

Result(s):

Connector is not cracked or broken or the connector will not lock.

Proceed to next step.

Connector is cracked or broken or the connector will not lock.

Replace the connector. Packard Connectors cannot be serviced, replace the component or harness piece as required. STOP.

2: Check Connector Pins/Wires

a. Apply 45 N (10 lb) of pull to each pin. Pins should always be crimped onto the wire using the 1U5804 Deutsch Crimp Tool. Do not solder pins or sockets.

Expected Result: Pin and connector remained in the connector body.

Result(s):

Pin and connector remained in the connector body.

Proceed to next step.

Pin and connector do not remain in the connector body.

Repair as needed. STOP.

3: Check Wires For Insulation Nicks Or Abrasion

a. Carefully inspect each wire for signs of abrasion, nicks, or cuts. Likely locations to check are anywhere the insulation is exposed, points where the wire rubs against the engine or a sharp point.

b. Check all harness hold down clamps to verify that the harness is properly clamped and the clamp is not compressing the harness. Pull the harness sleeves away to check for flattened wires where the clamp holds the harness.

Expected Result: Wires are not flattened and there are no signs of nicks or cuts.

Result(s):

Wires are not flattened and there are no signs of nicks or cuts.

Proceed to next step.

Wires are flattened or there are signs of nicks or cuts.

Repair as needed. STOP.

4: Check Connectors For Moisture Or Corrosion

a. Ensure the connector seals and white sealing plugs are in place.

b. Check wiring harness to verify the harness does not make a sharp bend out of the connector. This will deform the connector seal and create a moisture entry path.

NOTE: The electrical contacts/plugs are waterproof however, there can be contamination on the plug contacts. This can cause an overheat condition. Disconnect the plugs and wash the pin contacts with a no residue contact cleaner before replacing sensor(s) or valve.

Expected Result: No missing seals and no sharp bend out of the connector.

Result(s):

No missing seals and no sharp bend out of the connector.

Proceed to next step.

Missing seals or a sharp bend out of the connector.

Repair or replace wiring or connector as necessary. STOP.

5: Check Connector Pins And Sockets

a. Verify that pins and sockets are not damaged.

b. Verify proper alignment and location of pins in the connector.

Expected Result: Pins/Sockets are not damaged and are properly aligned in the connector.

Result(s):

Pins/Sockets are not damaged and are properly aligned in the connector.

Proceed to next step.

Pins/Sockets are damaged or not properly aligned in the connector.

Repair as needed. STOP.

6: Check Individual Pin Retention Into The Socket

a. Using a new pin, insert the pin into each socket one at a time to check for good grip on the pin by the socket.

b. Using a new socket, insert the socket onto each pin one at a time to check for good grip on the pin by the socket.

Expected Result: There is good pin retention.

Result(s):

There is good pin retention.

Continue troubleshooting Probable Cause:

Defective Air Conditioner Switch.

There is not good pin retention

Repair as required. STOP.

3. Defective Air Conditioner Switch

1: Check The Air Conditioner Switch For Proper Operation

a. Turn engine OFF.

b. Disconnect the air conditioner switch from the wiring harness.

c. Start the engine.

Expected Result: The fan clutch is engaged.

Result(s):

The fan clutch is engaged.

Continue troubleshooting Probable Cause:

Defective Aftercooler Switch.

The fan clutch is not engaged

Replace the air conditioner switch. STOP.

4. Defective Aftercooler Switch

1: Check The Aftercooler Switch For Proper Operation

a. Turn engine OFF.

b. Disconnect the aftercooler switch from the wiring harness.

c. Start the engine.

Expected Result: The fan clutch is engaged.

Result(s):

The fan clutch is engaged.

Continue troubleshooting Probable Cause:

Defective Brake Oil Switch.

The fan clutch is not engaged.

Replace the aftercooler switch. STOP.

5. Defective Brake Oil Switch

1: Check the brake oil switch for proper operation.

a. Turn engine OFF.

b. Disconnect the brake oil switch from the wiring harness.

c. Start the engine.

Expected Result: The fan clutch is engaged.

Result(s):

The fan clutch is engaged.

Continue troubleshooting Probable Cause:

Defective Coolant Sensor.

The fan clutch is not engaged.

Replace the brake oil switch. STOP.

6. Defective Coolant Sensor

1: Check The Coolant Sensor For Proper Operation

a. Turn engine OFF.

b. Disconnect the coolant sensor from the wiring harness.

c. Start the engine.

Expected Result: The fan clutch is engaged.

Result(s):

The fan clutch is engaged.

Continue troubleshooting problems with the cooling system. Refer to Systems Operation Testing & Adjusting Manual of the service manual.

The fan clutch is not engaged.

Replace the coolant sensor. STOP.

Oil Leakage At The Front Or Rear Face

Probable Cause(s):

* Incorrect Bolts (Fan To Hub)

* Orifice Not Installed In The "Oil In" Port (All Models Except D10)

* Restriction In The Oil Drain Line

* Oil Seals

* Wear Sleeve

1. Incorrect Bolts (Fan To Hub)

If the bolts that hold the fan to the hub are too long and contact the pulley then replace with the correct bolts. If the leak continues then repair or replace the fan clutch.

2. Orifice Not Installed In The "Oil In" Port

Install the orifice. If the leak continues then repair or replace the fan clutch.

3. Restriction In The Oil Drain Line

Remove restriction.

4. Oil Seals

Rebuild. Refer to Disassembly And Assembly in this service manual.

NOTE: A leaking hose connection may appear to be a seal leak. Check carefully.

5. Wear Sleeve

Rebuild. Refer to Disassembly And Assembly in this service manual.

Troubleshooting (100-8105 Fan Clutch)

This troubleshooting guide can be an aid for the service personnel to find the cause of existing problems with the fan clutch. Several common problems are covered in the guide.

Whenever the cause of the problem is found and corrected, stop the test (as shown by STOP). Do not continue through the complete procedure just because it is there.

Troubleshooting Problem List

Fan Does Not Lock Up, Fan Runs Slowly 20

Fan Runs Continuously 21

Oil Leakage at the rear face of the fan clutch 23

Fan Does Not Lock Up, Fan Runs Slowly

Probable Cause(s):

* Defective Coolant Or Brake Oil Sensor

* Defective Fan Clutch Solenoid Valve

1. Defective Coolant Or Brake Oil Sensor

1: Check The Electrical System Of The Fan Clutch Control System

a. Disconnect the fuse for the control system with the engine running.

Expected Result: The fan clutch is fully engaged.

Result(s):

The fan clutch is fully engaged.

Proceed to next step.

The fan clutch is not fully engaged.

Continue troubleshooting Probable Cause:

Defective Fan Clutch Solenoid Valve.

2: Check The Coolant And Brake Oil Sensor For Operation

a. Turn the ignition key ON, engine OFF.

b. Use the 7X1708 or the 7X1709 Knife Connector to ground pin-C of the coolant sensor to the frame of the engine.

c. Listen for the solenoid valve to "click" (you will need to be near the engine to hear the solenoid valve "click").

Expected Result: The solenoid valve "clicks".

Result(s):

The solenoid valve "clicks".

Replace the coolant temperature sensor. STOP.

The solenoid valve does not "click".

Replace the brake oil sensor. STOP.

2. Defective Fan Clutch Solenoid Valve

1: Check Oil Lines For The Proper Connections To The Fan Clutch

a. Confirm that the fan clutch control oil line, oil supply line (lubrication in), and oil drain line (lubrication out) are connected to the appropriate fittings on the fan clutch.

Expected Result: Oil lines are correctly connected to the fan clutch.

Result(s):

Oil lines are correctly connected to the fan clutch.

Replace the fan clutch solenoid valve. STOP.

Oil Lines are not correctly connected to the fan clutch.

Reconnect the lines to the proper connection fittings. STOP.

Fan Runs Continuously

Probable Cause(s):

* Defective Fan Clutch Solenoid Valve

* Defective Connectors And/Or Wires

* Defective Relay

* Defective Air Conditioner Switch

* Defective Air Conditioner And/Or Aftercooler Switch

* Defective Coolant And/Or Brake Oil Sensor

1. Defective Fan Clutch Solenoid Valve.

1: Check The Fuse For The Fan Clutch Control System

a. Turn the engine OFF.

b. Inspect the fuse.

Expected Result: The fuse is not blown.

Result(s):

The fuse is not blown.

Proceed to next step.

The fuse is blown.

Replace the fuse. STOP.

2: Check For Fan Clutch Solenoid Valve Resistance

a. Unplug valve wiring.

b. Use the 6V7070 Digital Multimeter on the DC setting and 7X1708, 7X1709 Knife Connectors to measure the resistance across pin-1 and pin-2.

Expected Result: The fan clutch solenoid valve resistance is 1.5 to 5 Ohms.

Result(s):

The fan clutch solenoid valve resistance is not 1.5 to 5 Ohms.

Replace the fan clutch solenoid valve.

The fan clutch solenoid valve resistance is 1.5 to 5 Ohms.

Continue troubleshooting Probable Cause:

Defective Connectors And/Or Wires

2. Defective Connectors And/Or Wires

1: Check Electrical Connectors And Wiring

a. Ensure the connectors are properly locked (clicked) together and the two halves cannot be pulled apart.

b. Inspect Packard Connectors, make sure the sensor is latched on both sides.

Expected Result: Connector is not cracked or broken or the connector will not lock.

Result(s):

Connector is not cracked or broken or the connector will not lock.

Proceed to next step.

Connector is cracked or broken or the connector will not lock.

Replace the connector. Packard Connectors cannot be serviced, replace the component or harness piece as required. STOP.

2. Check Connector Pins/Wires

a. Apply 45 N (10 lb) of pull to each pin. Pins should always be crimped onto the wire using the 1U5804 Deutsch Crimp Tool. Do not solder pins or sockets.

Expected Result: Pin and connector remained in the connector body.

Result(s):

Pin and connector remained in the connector body.

Proceed to next step.

Pin and connector do not remain in the connector body.

Repair as needed. STOP.

3: Check Wires For Insulation Nicks Or Abrasion

a. Carefully inspect each wire for signs of abrasion, nicks, or cuts. Likely locations to check are anywhere the insulation is exposed, points where the wire rubs against the engine or a sharp point.

Expected Result: Wires are not flattened and there are no signs of nicks or cuts.

Result(s):

Wires are not flattened and there are no signs of nicks or cuts.

Proceed to next step.

Wires are flattened or there are signs of nicks or cuts.

Repair as needed. STOP.

4: Check Connectors For Moisture Or Corrosion

a. Ensure the connector seals and white sealing plugs are in place.

b. Check wiring harness to verify the harness does not make a sharp bend out of the connector. This will deform the connector seal and create a moisture entry path.

Expected Result: No missing seals and no sharp bend out of the connector.

Result(s):

No missing seals and no sharp bend out of the connector.

Proceed to next step.

Missing seals or a sharp bend out of the connector.

Repair or replace wiring or connector as necessary. STOP.

5: Check Connector Pins And Sockets

a. Verify that pins and sockets are not damaged.

b. Verify proper alignment and location of pins in the connector.

Expected Result: Pins/Sockets are not damaged and are properly aligned in the connector.

Result(s):

Pins/Sockets are not damaged and are properly aligned in the connector.

Proceed to next step.

Pins/Sockets are damaged or not properly aligned in the connector.

Repair as needed. STOP.

6: Check Individual Pin Retention Into The Socket

a. Using a new pin, insert the pin into each socket one at a time to check for good grip on the pin by the socket.

b. Using a new socket, insert the socket onto each pin one at a time to check for good grip on the pin by the socket.

Expected Result: There is good pin retention.

Result(s):

There is good pin retention.

Continue troubleshooting Probable Cause:

Defective Air Conditioner And/Or Aftercooler Switch.

There is not good pin retention

Repair as required. STOP.

3. Defective Relay

1: Check For Output Voltage

a. Turn the ignition key ON, engine OFF.

b. Use the 6V7070 Digital Multimeter on the DC setting and 7X1708, 7X1709 Knife Connectors to measure the voltage from pin-30 to pin-87 of the relay.

Expected Result: The voltage is 24 VDC.

Result(s):

The voltage is 24 VDC.

Proceed to next step.

The voltage is not 24 VDC.

Continue troubleshooting Probable Cause:

Defective Coolant And/Or Brake Oil Sensor.

2: Check For Supplied Voltage

a. Turn the ignition key ON, engine OFF.

b. Use the 6V7070 Digital Multimeter on the DC setting and 7X1708, 7X1709 Knife Connectors to measure the voltage from pin-85 to pin-86 of the relay.

Expected Result: The voltage is 24 VDC.

Result(s):

The voltage is 24 VDC.

Continue troubleshooting Probable Cause:

Defective Air Conditioner And/Or Aftercooler Switch.

The voltage is not 24 VDC.

Replace the relay. STOP.

4. Defective Air Conditioner And/Or Aftercooler Switch

1: Check The Air Conditioner Switch For Proper Operation

a. Turn engine OFF.

b. Disconnect the air conditioner switch from the wiring harness.

c. Start the engine.

Expected Result: The fan clutch is engaged.

Result(s):

The fan clutch is engaged.

Replace the aftercooler switch. STOP.

The fan clutch is not engaged

Replace the air conditioner switch. STOP.

5. Defective Coolant And/Or Brake Oil Sensor

1: Check The Coolant Sensor For Voltage

a. Turn the ignition key ON, engine OFF.

b. Use the 6V7070 Digital Multimeter on the DC setting and 7X1708, 7X1709 Knife Connectors to measure the voltage from pin-D to pin-E of the coolant sensor.

Expected Result: The voltage is 24 VDC.

Result(s):

The voltage is 24 VDC.

Replace the brake oil sensor. STOP.

The voltage is not 24 VDC.

Replace the coolant sensor. STOP.

Oil Leakage At The Rear Face

Probable Cause(s):

* Incorrect Bolts

* Incorrect Orifice Installed In The "Oil In" Port

* Restriction In The Oil Drain Line

* Incorrect Belt Tension

* Oil Seals

* Wear Sleeve

1. Incorrect Bolts

If the bolts used are too long and contact the pulley then replace with the correct bolts. If the leak continues then repair or replace the fan clutch.

2. Incorrect Orifice Installed In The "Oil In" Port

Install the correct orifice. If the leak continues then repair or replace the fan clutch.

3. Restriction In The Oil Drain Line

Remove restriction.

4. Incorrect Belt Tension

Check that the belt tensioning mechanism is not bound up, misaligned, or creating excess tension. Refer to the belt tensioning chart in the specifications module for proper tightening.

5. Oil Seals

Rebuild. Refer to Disassembly And Assembly in this service manual.

NOTE: A leaking hose connection may appear to be a seal leak. Check carefully.

6. Wear Sleeve

Rebuild. Refer to Disassembly And Assembly in this service manual.