AC Clutch Coil

Replace the AC compressor clutch coil on a 1970 AMC Rebel Machine with 390ci V8 engine to restore air conditioning engagement capability.

Warnings

Tools required

Parts

• AC compressor clutch coil × 1 — Use OEM specification or aftermarket equivalent for York/Tecumseh compressor
• Wire connectors (if harness damaged) × 2 — Use OEM specification
• Clutch shim set × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cool
2. Disconnect negative battery cable
3. Verify access to compressor - may require removing fan shroud or repositioning radiator hoses for clearance
4. Take photo of wire routing and connections for reference
5. Test existing coil resistance with multimeter (should be 3-5 ohms) to confirm failure before proceeding

Procedure

1. 1

   Disconnect clutch coil wiring
   Locate the wire connector at the AC compressor clutch coil. Disconnect the single or double wire connector from the coil terminal. Note the wire routing for reinstallation. Use multimeter to verify coil resistance - a failed coil typically shows infinite resistance or less than 2 ohms.
2. 2

   Remove clutch hub snap ring
   Locate the large external snap ring on the front of the clutch hub (the center rotating portion). Using external snap ring pliers, carefully compress and remove the snap ring. Keep snap ring in a safe place for reinstallation. The clutch hub may now have slight axial movement.
3. 3

   Remove clutch hub assembly
   Install clutch hub puller onto the hub face using the threaded holes or center bolt access. Evenly tighten the puller to draw the hub off the compressor shaft. The hub is typically pressed on with a light interference fit. Note any shims behind the hub and keep them in order for proper air gap adjustment during reassembly.
4. 4

   Remove pulley snap ring
   With the hub removed, locate the internal snap ring inside the pulley assembly that retains the bearing and pulley to the compressor nose. Use internal snap ring pliers to compress and remove this snap ring. Work carefully as the pulley is supported by the bearing.
5. 5

   Remove pulley and bearing assembly
   Carefully slide the pulley and bearing assembly forward off the compressor nose. The assembly may require gentle persuasion with light tapping on opposite sides. The clutch coil will now be visible in its mounting groove on the compressor body.
6. 6

   Remove coil retaining hardware
   Locate the coil retaining snap ring or wire clip in the groove on the compressor nose that holds the coil in place. Using snap ring pliers or needle nose pliers, remove this retaining device. On some units, a small screw may secure the coil lead - remove if present.
7. 7

   Extract failed clutch coil
   Carefully pry the old coil assembly out of its mounting cavity in the compressor nose. Work around the circumference evenly to avoid damaging the coil mounting surfaces. Remove and discard the old coil. Clean any debris or corrosion from the coil mounting cavity using shop rags.
8. 8

   Install new clutch coil
   Position the new clutch coil into the mounting cavity on the compressor nose, ensuring the wire lead exits in the correct orientation matching your reference photo. Press the coil firmly into place until fully seated. The coil should sit flush in its mounting groove.
9. 9

   Secure new coil
   Install the retaining snap ring or wire clip into the groove to secure the coil. Ensure the retaining device is fully seated in its groove around the entire circumference. If applicable, secure the coil lead with the mounting screw.
10. 10

    Reinstall pulley and bearing assembly
    Slide the pulley and bearing assembly back onto the compressor nose, positioning it over the newly installed coil. Ensure it seats fully against the compressor body. Install the internal snap ring to secure the pulley assembly, ensuring the snap ring is fully seated in its groove.
11. 11

    Set clutch air gap and install hub
    Install the original shims onto the compressor shaft. Press the clutch hub onto the shaft until it contacts the shims. Install the external snap ring. Using feeler gauges, measure the air gap between the clutch hub face and pulley friction surface at three points around the circumference. Gap should be 0.015" to 0.030". Add or remove shims behind the hub as needed to achieve proper clearance.
12. 12

    Connect clutch coil wiring
    Route the coil wire lead following your reference photo. Connect the wire connector to the coil terminal. If the connector is damaged, cut and install new wire connectors, ensuring proper crimp connections. Secure any wire routing clips to prevent contact with moving components.

Reassembly

1. Reinstall any fan shroud or components removed for access
2. Reconnect negative battery cable
3. Double-check that all snap rings are fully seated and secure

Verification

• Turn ignition to ON position (engine off) and activate AC controls
• Listen for audible click as clutch engages
• Visually confirm clutch hub rotates with pulley when engaged
• Start engine and verify AC compressor engages smoothly without excessive noise or vibration
• Confirm clutch disengages completely when AC is turned off
• Check that clutch air gap remains within 0.015" to 0.030" specification after operation

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