Cooling Fan Relay

Replace the cooling fan relay on a 1992 Dodge Viper 8.0L V10, located in the power distribution center near the battery.

Warnings

Tools required

Parts

• Cooling fan relay × 1 — Use OEM specification

Preparation

1. Park the vehicle on level ground and apply the parking brake.
2. Turn the ignition off and remove the key.
3. Allow the engine to cool completely if recently operated.
4. Open the hood and secure it in the open position.
5. Locate the battery in the rear driver-side compartment area.

Procedure

1. 1

   Disconnect battery negative terminal
   Access the battery in the rear driver-side compartment. Using a wrench or socket (commonly 10mm), loosen the negative battery terminal clamp bolt. Remove the negative cable from the battery post and position it away from the terminal to prevent accidental reconnection during the repair.
2. 2

   Locate the power distribution center
   The power distribution center (PDC) is located in the engine compartment on the driver side fenderwell area. It is a black plastic enclosure containing fuses and relays. Note that the battery on the 1992 Viper is located in the rear of the vehicle, not in the engine compartment. It is a black plastic enclosure containing fuses and relays. Identify the PDC cover which should have a diagram indicating relay positions.
3. 3

   Remove power distribution center cover
   Release the cover retaining tabs by pressing or lifting them as required. The PDC cover typically has multiple spring clips or tabs that secure it. Lift the cover away to expose the fuses and relays inside. Inspect the underside of the cover for the relay identification diagram.
4. 4

   Identify the cooling fan relay
   Using the diagram on the PDC cover or in the owner's manual, locate the cooling fan relay. Verify the exact relay type against the diagram on the PDC cover or factory service documentation before ordering a replacement, as pin count and style vary by application. Note the relay position and orientation, including which direction the connector terminals face. Take a photo if needed for reference during installation.
5. 5

   Remove the cooling fan relay
   Grip the relay body firmly and pull straight up with steady pressure to remove it from the socket. The relay is held in place by friction-fit blade terminals. If the relay is difficult to remove, gently rock it side-to-side while pulling upward. Do not use excessive force or pry tools that could damage the socket terminals.
6. 6

   Inspect relay socket and terminals
   Examine the relay socket for corrosion, dirt, heat damage, or bent terminals. Check each terminal for proper spring tension and contact integrity. If corrosion or contamination is present, spray electrical contact cleaner into the socket and allow it to dry completely. If terminals are damaged or loose, the entire PDC may require replacement or professional repair.
7. 7

   Install the new cooling fan relay
   Align the new relay with the socket, ensuring the terminal blade orientation matches the socket configuration. Press the relay firmly into the socket until it is fully seated and the base of the relay contacts the PDC housing. The relay should sit flush without gaps. Apply light dielectric grease to the relay terminals before installation if desired for corrosion protection.
8. 8

   Reinstall power distribution center cover
   Position the PDC cover over the fuse and relay assembly, aligning all tabs and clips. Press down firmly on all edges of the cover until all retaining tabs click into place and the cover is secure. Verify the cover is completely seated to maintain weather protection.
9. 9

   Reconnect battery negative terminal
   Place the negative cable back onto the battery negative post. Tighten the 10mm clamp bolt securely, ensuring good electrical contact. Do not overtighten as this may damage the battery post or clamp.

Reassembly

1. Ensure all power distribution center cover tabs are fully engaged and the cover is weather-tight.
2. Verify the battery negative terminal is tight and secure.
3. Confirm no tools or parts were left in the engine compartment.

Verification

• Start the engine and allow it to reach normal operating temperature while monitoring the temperature gauge.
• The cooling fan should activate automatically when the coolant temperature reaches the thermostat setpoint (typically around 220°F).
• Listen for the cooling fan motor engagement and verify airflow through the radiator.
• If the fan does not activate, turn on the air conditioning. The cooling fan should activate immediately with the A/C compressor.
• Check for any warning lights on the instrument cluster related to engine temperature.
• Turn off the engine and verify the fan stops. If equipped with a high-temperature shutoff feature, the fan may continue running briefly after engine shutdown if coolant temperature is elevated.

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle