Replace the floor-mounted dimmer switch on a 1966 Chevrolet Corvette, restoring proper high/low beam headlight functionality.

Warnings

Tools required

Parts

• Floor-mounted dimmer switch × 1 — Use OEM specification or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect the negative battery cable
3. Allow interior to cool if vehicle has been running
4. Remove any floor mats or carpet blocking access to the dimmer switch

Procedure

1. 1

   Locate the dimmer switch
   Identify the dimmer switch mounted on the floor pan to the left of the transmission tunnel. The switch is operated by a foot pedal and has two wiring connectors attached to its terminals.
2. 2

   Disconnect the wiring
   Disconnect the two wire terminals from the dimmer switch. Note the position of each wire for proper reinstallation. The wires are typically push-on spade terminals that can be pulled straight off by hand or with gentle prying using a flathead screwdriver.
3. 3

   Remove the mounting bolts
   Remove the two 7/16" mounting bolts securing the dimmer switch to the floor pan. The switch is mounted with the actuator button facing upward toward the foot pedal.
4. 4

   Remove the old dimmer switch
   Lift the dimmer switch away from the floor pan. If present, retrieve the foot pedal actuator button that sits on top of the switch plunger.
5. 5

   Clean the mounting area
   Use a wire brush to clean the mounting surface on the floor pan and remove any rust or corrosion. This ensures proper electrical ground for the new switch.
6. 6

   Position the new dimmer switch
   Place the new dimmer switch on the floor pan with the actuator plunger facing upward. Align the mounting holes with the holes in the floor pan. If applicable, position the foot pedal actuator button on top of the switch plunger.
7. 7

   Install the mounting bolts
   Thread in the two 7/16" mounting bolts finger-tight, then snug them down firmly with a wrench. Do not overtighten, as this can crack the switch housing or strip the floor pan threads. The switch should be secure but not excessively torqued.
8. 8

   Connect the wiring
   Reconnect the two wire terminals to the dimmer switch terminals. Ensure each terminal is pushed fully onto the switch blade and makes solid contact. Typically, one wire is the feed from the headlight switch and the other wires route to the high and low beam circuits; verify each terminal against your noted positions from disassembly.
9. 9

   Reconnect the battery
   Reconnect the negative battery cable to restore power to the vehicle's electrical system.

Reassembly

1. Replace any carpet or floor mats that were removed for access
2. Verify the dimmer switch actuator pedal operates smoothly without binding

Verification

• Turn the headlight switch to the ON position
• Press the dimmer switch with your foot to verify it toggles between high and low beams
• Confirm both high beams illuminate when the switch is in the high beam position
• Confirm both low beams illuminate when the switch is in the low beam position
• Check that the high beam indicator light on the instrument cluster illuminates with high beams
• Verify the switch returns to its rest position after each press

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