This procedure covers the removal and replacement of a faulty seat heater element in the 2023 Rivian EDV 500, requiring partial disassembly of the seat upholstery and replacement of the heating pad.

Warnings

Tools required

Parts

• Seat heater element pad × 1 — Use OEM specification for specific seat position
• Hog rings × 20 — Stainless steel upholstery hog rings
• Seat heater connector pigtail (if damaged) × 1 — Use OEM specification
• Wire connectors/terminals × 4 — Heat-shrink butt connectors

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect 12V auxiliary battery negative terminal and wait 2 minutes for system capacitors to discharge
3. If working on driver seat, move seat fully rearward and down for access. If passenger seat, move fully forward and down
4. Photograph all wiring routing and connector positions for reference
5. Test the existing heater element with multimeter to confirm failure before proceeding (should read 1.5-3.0 ohms between terminals)

Procedure

1. 1

   Remove seat from vehicle
   Locate the four seat track mounting bolts at each corner of the seat base. Remove all four Torx bolts securing the seat tracks to the floor pan. Carefully tilt the seat back to access the wiring harness underneath. Disconnect the main seat harness connector (large multi-pin connector), then carefully lift the seat assembly out of the vehicle and place on a clean work surface.
2. 2

   Disconnect seat heater connector
   Locate the seat heater connector on the underside of the seat cushion. This is typically a 2-pin connector separate from the main harness. Press the locking tab and disconnect the heater element connector. Use multimeter to verify which connector leads to the heater element (check continuity with heating pad).
3. 3

   Remove seat cushion covers
   Turn the seat upside down to access the bottom of the seat cushion. Locate all hog rings securing the seat cover to the cushion frame around the perimeter. Use hog ring pliers to carefully compress and remove each hog ring - there are typically 15-25 rings around the cushion. Note the position of each ring for reinstallation. Carefully pull the seat cover away from the foam cushion, working gradually around the perimeter.
4. 4

   Access the heater element
   With the seat cover partially removed, locate the seat heater element pad sandwiched between the foam cushion layers. The element will be a thin fabric pad with wire leads. Carefully peel back the seat foam if necessary to expose the full heater pad. Note the orientation and exact position of the heating element within the cushion before removal.
5. 5

   Remove old heater element
   The heater element is typically bonded to the foam with adhesive. Carefully peel the old heater element away from the foam cushion, working slowly to avoid tearing the foam. If the element is heavily adhered, use a plastic trim tool to help separate it. Remove any remaining adhesive residue from the foam surface. Follow the wire leads to where they exit the cushion and carefully route them out.
6. 6

   Prepare new heater element
   Unpack the new heater element and verify it matches the old element in size and connector type. If the new element has different connectors, prepare the connector pigtail for splicing. Test the new element with a multimeter to confirm proper resistance (should read 1.5-3.0 ohms). Ensure the element is clean and free from manufacturing oils or debris.
7. 7

   Install new heater element
   Apply heat-resistant adhesive spray to the foam cushion area where the heater element will be positioned. Wait for adhesive to become tacky per manufacturer instructions (typically 30-60 seconds). Carefully position the new heater element in the exact location of the original, ensuring proper orientation with heating zones aligned to seating areas. Press firmly but gently to bond the element to the foam. Route the wire leads through the same path as the original.
8. 8

   Connect heater element wiring
   If connectors match, simply route wiring to the connection point. If splicing is required, strip wire ends 1/4 inch, insert into heat-shrink butt connectors matching wire gauge, and crimp securely. Ensure all connections are properly insulated and moisture-resistant. Route all wiring away from seat frame pinch points and moving components. Secure wiring with existing clips or add new clips as needed.
9. 9

   Test heater element function
   Before reassembling the seat cover, reconnect the 12V battery temporarily. Reconnect the seat heater connector and the main seat harness connector. Start the vehicle and activate the seat heater function. Allow 2-3 minutes for the element to warm up. Carefully feel the cushion surface to verify even heating across the pad area. Use a non-contact infrared thermometer if available to verify proper temperature (should reach 95-110°F). If heating is uneven or non-functional, recheck all connections.
10. 10

    Reinstall seat cushion cover
    Once heating function is verified, disconnect battery again for safety. Position the seat cover back over the cushion, aligning all seams and ensuring the cover sits properly without wrinkles or bunching. Working around the perimeter, reinstall new hog rings in the original locations using hog ring pliers. Ensure even tension on the cover - not too tight or too loose. Verify the cover is properly seated around all edges and corners.
11. 11

    Reinstall seat in vehicle
    Carefully lift the seat assembly and position it over the mounting points in the vehicle. Tilt the seat forward to access the wiring harness area. Reconnect the main seat harness connector, ensuring it clicks into place securely. Reconnect the seat heater connector. Lower the seat into position, aligning all four mounting bolt holes with the floor pan threaded inserts. Install all four seat track mounting bolts and tighten in a cross pattern to ensure even seating.

Reassembly

1. Ensure all seat mounting bolts are fully tightened in a cross pattern
2. Verify all electrical connectors are fully seated with locking tabs engaged
3. Check that no wiring is pinched between seat components or under the seat tracks
4. Verify seat can move freely on tracks without binding or interference
5. Reconnect 12V battery negative terminal

Verification

• Start the vehicle and verify no warning lights appear on the instrument cluster related to seat systems
• Test seat heater function through all heat settings (low, medium, high if equipped) and verify even heating
• Allow heater to run for 5 minutes and verify it reaches appropriate temperature without overheating
• Test seat position adjustments to ensure no interference with new wiring routing
• If equipped, verify seat occupancy sensor still functions (seatbelt warning light should activate with passenger weight)
• Inspect seat cover for proper fit and appearance with no wrinkles or loose areas

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