This procedure addresses a repair request for heated seat module service on a 1966 Chevrolet Corvette. However, the 1966 Corvette did not come equipped with heated seats from the factory, so this procedure covers diagnosis and removal of any aftermarket heated seat system that may have been installed.

Warnings

Tools required

Parts

• Heated seat module (aftermarket) × 1 — Match existing aftermarket system brand
• Wire connectors and terminals × 1 — Assorted butt connectors and ring terminals
• Electrical tape × 1 — 3M Super 33+ or equivalent
• Wire loom or heat shrink tubing × 1 — Assorted sizes

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable and isolate from battery post
3. Allow any recently operated heated seats to cool completely (minimum 30 minutes)
4. Locate heated seat controller switches (typically dash-mounted or center console in aftermarket installations)
5. Take photos of existing wiring connections and switch positions for reference during reinstallation
6. Identify the location of the heated seat module (commonly under driver or passenger seat, or behind kick panel)

Procedure

1. 1

   Remove seat track covers and locate module
   Working from inside the vehicle, locate the aftermarket heated seat module. In most aftermarket installations, the module will be mounted under the seat, attached to the seat frame or floor pan. Remove any carpet or trim pieces blocking access to the seat mounting bolts. The 1966 Corvette seats are bolted to the floor via seat risers/tracks; verify the exact bolt count and locations against the factory assembly/service manual before removal, as the arrangement differs from later vehicles.
2. 2

   Document existing wiring configuration
   Before disconnecting anything, use your phone or camera to photograph all wiring connections to the heated seat module. Note wire colors, connector orientations, and routing paths. Use masking tape and a marker to label each wire with its destination (e.g., 'to driver seat', 'to switch', 'to power', 'to ground'). This documentation is critical as aftermarket installations vary widely.
3. 3

   Test system before removal
   Reconnect the battery temporarily. Use your multimeter to test for power at the module input when the heated seat switch is activated. Check for proper ground continuity. Test voltage output to the heating elements (typically 12V DC). Record all voltage readings. This baseline testing helps determine if the module is actually faulty or if the problem lies elsewhere in the system. Disconnect battery again before proceeding.
4. 4

   Remove seat mounting bolts
   Remove the 4 seat mounting bolts securing the seat to the floor tracks. These are typically 1/2" or 7/16" head bolts. Slide the seat fully forward to access the rear mounting bolts, then slide fully rearward to access the front bolts. Carefully tilt the seat backward to expose the underside and provide working access to the module without fully removing the seat from the vehicle.
5. 5

   Disconnect module power and ground
   Locate the main power wire connection to the heated seat module (typically a red wire connected to a switched or unswitched 12V source, often tapped from the fuse panel or cigarette lighter circuit). Disconnect this power connection at the module. Locate and disconnect the ground wire (typically black wire connected to a chassis ground point or seat frame). Remove any zip ties or wire loom securing these wires.
6. 6

   Disconnect control switch wiring
   Trace the wiring from the heated seat control switch to the module. This may run under the carpet, along the door sill, or through the center console depending on the aftermarket installation. Disconnect the switch wiring at the module. If the connector is not a quick-disconnect type, carefully cut the wires leaving adequate length for splicing during reinstallation, and label each wire.
7. 7

   Disconnect heating element wiring
   Locate the wiring connections between the module and the actual heating elements in the seat. Most aftermarket systems use quick-disconnect connectors or inline fuse holders. Disconnect both the driver seat heating element connections (typically 2 wires for the seat bottom heating pad and 2 wires for the seat back heating pad if equipped). If dealing with a dual-seat system, disconnect passenger side connections as well.
8. 8

   Remove module mounting hardware
   The module is typically secured to the seat frame or floor pan with 2 to 4 screws, bolts, or zip ties. Remove these fasteners and carefully extract the module from its mounting location. Note the exact mounting position and orientation for reinstallation of the new module.
9. 9

   Inspect heating element wiring and connections
   With the module removed and access available, inspect all wiring to and from the heating elements for damage, chafing, burns, or corrosion. Check that heating element connectors are not melted or discolored. Use your multimeter to check resistance across each heating element (typical values range from 2 to 8 ohms depending on element wattage). An open circuit indicates a failed heating element rather than a faulty module.
10. 10

    Prepare new module for installation
    Unpack the new heated seat module and verify it matches the specifications of the original unit (voltage rating, number of zones, amperage capacity). If the new module uses different connectors than the original, prepare appropriate wire splices or adapters. Apply dielectric grease to all connector terminals to prevent corrosion.
11. 11

    Mount new module
    Position the new module in the same location as the original, ensuring wiring will reach all connection points without tension. Secure the module using the original mounting hardware or the mounting brackets provided with the new unit. Ensure the module is mounted away from any moving seat components and will not be exposed to water intrusion.
12. 12

    Reconnect all wiring connections
    Working in reverse order of disconnection, reconnect all wiring to the new module. Connect heating element wiring first, then control switch wiring, then ground, and finally main power. If splicing wires, use proper crimp connectors and cover all splices with heat shrink tubing or high-quality electrical tape. Ensure all connections are secure and properly seated. Route all wiring away from seat tracks and moving components.
13. 13

    Reinstall seat assembly
    Return the seat to its upright position and align the mounting holes with the floor track bolt holes. Install all 4 seat mounting bolts and tighten securely. Ensure the seat slides freely on the tracks and that no wiring is pinched or interfering with seat movement.
14. 14

    Test system operation
    Reconnect the battery negative cable. Turn the ignition to the accessory or run position (or otherwise apply power per the specific aftermarket wiring, which may use a constant 12V source on this vehicle). Activate the heated seat switch and verify that the indicator light (if equipped) illuminates. Allow the system to operate for 5 minutes and carefully check that the seat is warming evenly. Use your multimeter to verify the module is delivering proper voltage to the heating elements (should match your baseline readings from step 3). Check that the module housing is not getting excessively hot during operation.

Reassembly

1. Reinstall any carpet or trim pieces removed for access
2. Secure all wiring with new zip ties to prevent future chafing or interference with seat operation
3. Verify seat operates smoothly through its full range of motion on the tracks
4. Test both heat settings (if dual-setting system) to confirm proper operation

Verification

• With ignition on and heated seat switch activated, verify seat begins to warm within 2-3 minutes
• Check that both seat bottom and seat back heating zones (if equipped) are functioning
• Verify no blown fuses after system operation
• Confirm no unusual odors, smoke, or excessive heat from module during operation
• Test system for at least 15 minutes of continuous operation to ensure module does not overheat or fail
• Verify all indicator lights and controls are functioning as designed
• Ensure seat slides and adjusts normally with no interference from wiring

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