Third Brake Light

Remove and replace the center high-mounted stop lamp (third brake light) assembly on the 2005 Dodge Viper, including bulb/LED module and housing replacement.

Warnings

Tools required

Parts

• Third brake light assembly (complete with housing) × 1 — Mopar 04857986AB or equivalent
• Third brake light bulb or LED module × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn ignition off and remove key
3. Allow vehicle to cool completely if recently operated (rear deck surface temperatures can exceed 150°F)
4. Open rear deck/trunk and secure in open position
5. Verify replacement part matches original configuration (bulb type, connector style, mounting pattern)

Procedure

1. 1

   Access third brake light from interior
   Open the rear decklid. The 2005 Viper is a convertible (roadster) only, so the third brake light (center high-mounted stop lamp) is located in the rear deck/decklid area, not near a coupe rear window. Use a work light to locate the back of the third brake light housing, accessing it from underneath the decklid or through the rear deck panel. Confirm the exact mounting location on your specific vehicle before proceeding. well.
2. 2

   Disconnect electrical connector
   Locate the wiring harness connector attached to the back of the third brake light assembly. Press the locking tab on the connector and pull straight away from the lamp housing to disconnect. If the connector is stiff, gently rock it side-to-side while pulling to avoid damaging the terminals.
3. 3

   Remove mounting fasteners
   Identify and remove the fasteners securing the third brake light housing to the deck panel. These are typically 2-3 fasteners accessible from the trunk side. Check for the fastener type used — this may be Phillips screws, Torx fasteners, or plastic push-clips. Verify the exact fastener type and size on your specific vehicle before selecting tools. Remove all fasteners completely and store them safely. If push-clips are present, use a flat-blade trim tool to depress the center pin, then extract the clip body. Note: Tighten the small housing fasteners snugly by hand only (do not use power tools) to avoid cracking the plastic housing or over-compressing the gasket. No high torque value is required for these lamp fasteners.
4. 4

   Remove third brake light assembly
   With all fasteners removed, carefully pull the third brake light assembly away from the mounting surface. It may be sealed with a gasket or weatherstrip, so apply gentle but firm pressure. Avoid twisting or bending the housing excessively. Once clear of the mounting hole, remove the assembly completely from the vehicle.
5. 5

   Inspect mounting surface and gasket
   Examine the mounting surface on the deck panel for cracks, corrosion, or water intrusion evidence. Check the condition of the rubber gasket or weatherstrip seal. If the gasket is compressed, cracked, or damaged, replace it with the new assembly. Clean any debris, old sealant, or corrosion from the mounting surface using a clean cloth.
6. 6

   Prepare new third brake light assembly
   Remove the new third brake light assembly from packaging. If replacing only the bulb or LED module, open the back cover of the existing housing (typically twists counter-clockwise or has small retaining tabs), remove the failed bulb/module, and install the new one. Ensure any gasket or seal is properly positioned on the new assembly before installation.
7. 7

   Install new assembly
   Position the new third brake light assembly into the mounting hole from the exterior side, aligning it properly with the deck panel contour. From inside the trunk, guide the wiring connector through and verify the gasket seats evenly around the perimeter. Hold the assembly in place while proceeding to fastener installation.
8. 8

   Install mounting fasteners
   Install and tighten the mounting fasteners from inside the trunk. If using screws, start all fasteners by hand first, then tighten in a cross-pattern to ensure even pressure on the gasket. For plastic push-clips, insert the clip body into the hole, then press the center pin until it sits flush. Tighten screws to specification to avoid cracking the housing or over-compressing the gasket.
9. 9

   Connect electrical connector
   Reconnect the wiring harness connector to the back of the third brake light assembly. Push the connector straight onto the lamp terminals until you hear or feel a positive click, indicating the locking tab has engaged. Gently tug on the connector to verify it is fully seated and locked.
10. 10

    Test third brake light operation
    Turn the ignition to the ON position (engine does not need to start). Have an assistant press the brake pedal while you observe the third brake light from outside the vehicle. Verify the light illuminates at full brightness and turns off when the pedal is released. Cycle the brake pedal several times to confirm consistent operation. If the light does not function, recheck the electrical connector and verify bulb/module installation.

Reassembly

1. Installation is the reverse of removal, following steps 6-9 as outlined
2. Ensure gasket is properly seated to prevent water intrusion into trunk area
3. Verify all fasteners are tightened to specification to avoid rattles or wind noise at highway speeds

Verification

• Third brake light illuminates at full brightness when brake pedal is depressed
• Light extinguishes completely when brake pedal is released
• No visible gaps between lamp housing and deck panel (indicates proper gasket seal)
• No rattles or vibrations from third brake light assembly at idle or while driving
• Conduct road test and verify third brake light operation during multiple brake applications
• Check for moisture or water intrusion in trunk area after car wash or rain (indicates failed gasket seal)

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