This procedure covers removal and replacement of the alternator on a 1966 Chevrolet Corvette with 327ci V8 engine, including belt adjustment and electrical connections.

Warnings

Tools required

Parts

• Alternator × 1 — Use OEM specification or Delco 1100693
• V-belt (alternator/generator belt) × 1 — Measure old belt length, typically 36-38 inches
• Alternator adjustment bracket bolt (if worn) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Open hood and secure with prop rod
3. Allow engine to cool if recently operated
4. Disconnect negative battery cable and secure away from battery post
5. Locate alternator on passenger side of engine, mounted low on the block with adjustment bracket toward front

Procedure

1. 1

   Disconnect alternator wiring
   Locate the two-wire connector on the rear of the alternator housing. Disconnect the two-terminal plug by pulling straight back. Remove the nut securing the battery positive wire to the output stud on the alternator rear housing (typically 1/2" nut). Remove the battery wire and any additional field wires from the stud. Note wire positions for reinstallation.
2. 2

   Release belt tension
   Locate the alternator adjustment bracket bolt on the long slot at the top of the alternator mounting bracket. This bolt threads into the alternator housing. Loosen this bolt several turns using a 9/16" wrench but do not remove it completely. Push the alternator toward the engine block to create slack in the V-belt.
3. 3

   Remove V-belt
   With tension released, slip the V-belt off the alternator pulley first, then remove it from the crankshaft pulley. Inspect belt for cracks, glazing, or fraying. If replacing belt, note belt routing before complete removal.
4. 4

   Remove alternator adjustment bolt
   Fully remove the adjustment bracket bolt from the slotted bracket at the top of the alternator. This bolt may be 3 to 4 inches long and passes through the adjustment slot.
5. 5

   Remove alternator pivot bolt
   Locate the lower pivot bolt that passes through the alternator mounting ear and threads into the engine block bracket. This is typically a 1/2" or 9/16" bolt head. Remove this bolt completely while supporting the alternator with your other hand.
6. 6

   Remove alternator from vehicle
   With both mounting bolts removed, carefully maneuver the alternator out of the engine bay. The alternator typically comes out toward the passenger side fender, tilting as needed to clear surrounding components. Watch for sharp edges on exhaust manifolds and brackets.
7. 7

   Inspect mounting brackets and hardware
   Examine the alternator mounting bracket on the engine block for cracks or damage. Inspect the adjustment bracket slot for wear or elongation. Clean mounting surfaces with a wire brush. Check that the pivot bolt threads in the engine block bracket are clean and undamaged. Inspect the adjustment bolt for thread damage or excessive wear.
8. 8

   Install new alternator
   Position the new or rebuilt alternator into the mounting bracket. Align the lower mounting ear with the pivot bolt hole in the engine block bracket. Insert the pivot bolt through the alternator ear and thread it into the engine block bracket finger-tight. Do not fully tighten yet.
   Torque spec

   Alternator Pivot Bolt25 Nm (18 lb-ft)
9. 9

   Install adjustment bracket bolt
   With alternator hanging on the pivot bolt, align the upper adjustment slot with the bracket. Insert the adjustment bracket bolt through the slot and thread it into the alternator housing. Leave this bolt loose to allow for belt tensioning.
10. 10

    Install and tension V-belt
    Route the V-belt around the crankshaft pulley first, then over the alternator pulley. Pull the alternator away from the engine block to create tension. Proper belt tension should allow approximately 1/2 inch of deflection when pressed firmly at the midpoint between pulleys. Once proper tension is achieved, hold the alternator in position and tighten the adjustment bracket bolt securely, then torque the pivot bolt to specification.
    Torque spec

    Alternator Pivot Bolt25 Nm (18 lb-ft)
11. 11

    Torque alternator mounting bolts
    With belt tensioned and adjustment bolt snug, torque the lower pivot bolt to 30 lb-ft. Then torque the upper adjustment bracket bolt to 18 lb-ft. Recheck belt tension after torquing and adjust if necessary. Verified detail (The torque values appear reversed/inconsistent. On a SBC the alternator pivot/mounting bolt is typically the larger fastener torqued around 30-35 lb-ft, while the adjustment (brace) bolt is the smaller fastener around 15-20 lb-ft. As written the small adjustment bolt is over-torqued and the pivot bolt under-torqued.): With belt tensioned and adjustment bolt snug, torque the lower pivot bolt to approximately 35 lb-ft. Then torque the upper adjustment bracket bolt to approximately 18 lb-ft. Verify both values against a model-specific service manual. Recheck belt tension after torquing and adjust if necessary.
    Torque spec

    Alternator Mounting Bolts50 Nm (37 lb-ft)

    Alternator Pivot Bolt25 Nm (18 lb-ft)
12. 12

    Reconnect alternator wiring
    Reconnect the battery positive wire to the output stud on the rear of the alternator. Install the retaining nut and tighten securely (approximately 5-7 lb-ft; do not overtighten the output stud). Reconnect the two-wire plug to the alternator terminals, ensuring it seats fully. Apply dielectric grease to connections if desired for corrosion protection.
13. 13

    Reconnect battery and perform initial test
    Reconnect the negative battery cable and torque the terminal bolt to specification. Before starting the engine, turn the ignition to the "ON" position (without cranking). On cars equipped with an alternator warning lamp, verify the lamp illuminates; on cars equipped with an ammeter, this step does not apply. The field circuit is supplied through the externally mounted voltage regulator. Verified detail (The 1966 Corvette base instrument cluster uses an ammeter gauge, not an idiot/warning light, for charging indication. Verifying via a warning light may not apply to this vehicle.): Before starting the engine, turn the ignition to the "ON" position (without cranking). Note that the 1966 Corvette typically uses an ammeter gauge rather than a charge warning light; verify the ammeter responds and wiring is correctly connected before proceeding.
    Torque spec

    Battery Terminal Bolts8 Nm (6 lb-ft)

Reassembly

1. Verify all electrical connections are secure and properly insulated
2. Confirm V-belt is properly seated in all pulley grooves and has correct tension
3. Double-check that both alternator mounting bolts are torqued to specification
4. Ensure no tools or parts are left in engine compartment

Verification

• Start engine and verify alternator warning light extinguishes within 1-2 seconds
• With engine running at idle, measure voltage at battery terminals; should read 13.8-14.5 volts indicating proper charging
• Increase engine speed to 2000 RPM and verify voltage remains stable between 13.8-14.8 volts
• Turn on headlights and other electrical accessories; voltage should remain above 13.5 volts at idle
• Listen for unusual bearing noise from alternator during operation
• Inspect belt after 5 minutes of running for proper tracking and no slippage

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