M11 Series – Service Manual – 008-026   Fan Clutch, Electric

WARNING  Batteries can emit explosive gases. To avoid personal injury, always ventilate the compartment before servicing the batteries. To avoid arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

Disconnect the electrical connections, negative (-) cable first, from the batteries.

Disconnect the fan clutch connector on the base harness from the fan clutch.

Remove the fan from the engine.

Loosen the fan idler pulley shaft locknut.

Turn the adjusting screw

counterclockwise to release the fan belt tension.

Remove the fan drive belt.

Remove the fan hub, clutch and capscrews from the engine.

This type of fan clutch is activated when 12 VDC from the vehicle electrical system is applied.

The clutch will disengage when 0 VDC is applied.

If the fan does

not operate within the temperature range on the coolant temperature sensor (1), the fan clutch and the controls

must be checked.

Electrical Connections

Inspect wires and harnesses to make sure none are broken or shorted. Replace harnesses or wires that are broken.

Refer to Procedure 008-069.

Electromagnetic Coil

The Cummins electric fan clutch contains an electromagnetic coil. If the fan is

not operating and all electrical circuits are OK, the coil possibly has an open circuit.

Measure the continuity across the isolated coil. Connect one multimeter lead to pin A in the fan clutch connector. Connect the other lead to pin B.

The resistance

must be within 6-10 ohms. If the resistance is

not within this range, replace the fan clutch.

Install the fan hub, clutch, and capscrews. Tighten the capscrews alternately and evenly.

Install the fan belt on the engine.

Refer to Procedure 008-002.

Install the fan and capscrews. Tighten the capscrews to the fan manufacturer’s specifications.

Connect the fan clutch connector on the base harness to the fan clutch.