Cooling Fan Relay

Replace the cooling fan relay in the Power Distribution Center (PDC) located in the engine compartment of a 2008 Dodge Viper with 8.4L V10 engine.

Warnings

Tools required

Parts

• Cooling fan relay × 1 — Use OEM specification - Mopar 4692327 or equivalent

Preparation

1. Ensure the engine is cool to the touch before beginning work.
2. Park the vehicle on a level surface and engage the parking brake.
3. Open the hood and secure it in the open position.

Procedure

1. 1

   Disconnect the battery negative terminal
   Using a socket wrench, loosen the negative battery terminal clamp and disconnect the negative cable from the battery. Secure the cable away from the battery terminal to prevent accidental reconnection during the repair. Note: Use OEM specification - match the relay part number stamped on the original relay or verify against Mopar parts documentation for the 2008 Viper.
2. 2

   Locate the Power Distribution Center
   The Power Distribution Center (PDC) is located in the engine compartment. Consult the factory service manual or the label on the PDC/fuse box cover to confirm its exact location on the 2008 Viper before proceeding. It is a black plastic box with a removable cover. Identify the PDC before proceeding.
3. 3

   Remove the PDC cover
   Release the cover retaining tabs or clips by gently prying them with a trim removal tool or your fingers. Lift the cover straight up and off the PDC. The underside of the cover contains a relay and fuse diagram showing the location of each component.
4. 4

   Identify the cooling fan relay
   Using the diagram on the underside of the PDC cover, locate the cooling fan relay. The relay will be labeled on the diagram, typically as 'RADIATOR FAN' or similar designation. The relay is a rectangular plug-in component with multiple terminals on the bottom.
5. 5

   Remove the old cooling fan relay
   Firmly grasp the cooling fan relay body and pull it straight up and out of its socket in the PDC. The relay should release with moderate force. If it is stuck, gently rock it side to side while pulling upward to break it free. Avoid prying against the PDC housing to prevent damage.
6. 6

   Inspect the relay socket
   Examine the relay socket terminals inside the PDC for any signs of corrosion, burning, or damage. If corrosion is present, clean the terminals with electrical contact cleaner and a small brush. If terminals are burned or damaged, the entire PDC may require replacement.
7. 7

   Install the new cooling fan relay
   Align the new cooling fan relay with its socket in the PDC, ensuring the terminal configuration matches the socket. Press the relay firmly straight down into the socket until it is fully seated and cannot be pushed further. The relay should sit flush with the surrounding relays.
8. 8

   Reinstall the PDC cover
   Position the PDC cover over the Power Distribution Center, aligning the cover with the housing. Press down firmly on all edges of the cover until the retaining tabs or clips snap into place and the cover is fully seated.
9. 9

   Reconnect the battery negative terminal
   Place the negative battery cable back onto the negative battery terminal and tighten the clamp securely with a socket wrench. Ensure the connection is tight to prevent electrical issues.

Reassembly

1. Ensure the PDC cover is fully secured with all clips or tabs engaged before closing the hood.
2. Verify that no tools or parts have been left in the engine compartment.

Verification

• Start the engine and allow it to reach operating temperature while monitoring the temperature gauge.
• Verify that the cooling fan engages automatically when the engine reaches the appropriate temperature threshold (typically around 210-220°F).
• Listen for proper fan operation without unusual noise or vibration.
• If the fan does not engage, turn on the air conditioning and verify that the fan operates, as this is another trigger for fan operation.
• Check for any warning lights on the instrument cluster related to cooling system operation.

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