Blower Motor Control Module

This procedure guides you through the removal and replacement of the blower motor control module (blower motor resistor) on a 1992 Dodge Viper, which controls blower motor speed settings.

Warnings

Tools required

Parts

• Blower motor control module (resistor) × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and set parking brake
2. Allow HVAC system to cool if recently operated
3. Disconnect negative battery terminal to prevent electrical shorts

Procedure

1. 1

   Locate the blower motor control module
   Open the passenger door and locate the blower motor control module. On the 1992 Viper, the blower motor resistor is typically mounted at or near the blower motor housing on the HVAC case. Its exact location should be confirmed against the factory service manual for this specific vehicle, as the Viper's HVAC layout differs from mass-production Dodge models. Look for the wiring harness connector and the resistor's cooling fins/heat sink. You may need to look up under the dash from the passenger footwell area. The module will have a wiring harness connector attached and cooling fins or a heat sink visible.
2. 2

   Disconnect the electrical connector
   Locate the electrical connector attached to the blower motor control module. Press the locking tab or release mechanism and pull the connector straight off the module. Do not pull on the wires themselves. Inspect the connector terminals for corrosion or damage.
3. 3

   Remove the module mounting fasteners
   Remove the mounting screws securing the blower motor control module to the HVAC housing. Blower resistors of this era are commonly held by 2 screws, but confirm the exact count and fastener type against the factory service manual for this vehicle. Use the appropriately sized socket or nut driver to remove these fasteners. Keep the fasteners in a safe location for reinstallation.
4. 4

   Remove the old module
   Pull the blower motor control module away from the HVAC housing. The module should slide straight out once the mounting screws are removed. Note the orientation of the module and the position of any alignment tabs or mounting flanges for proper installation of the new module.
5. 5

   Inspect the mounting area
   Check the mounting surface on the HVAC housing for debris, corrosion, or damage. Clean the mounting area if necessary. Verify that the cooling fins or heat sink area is free from obstruction, as proper airflow is critical for module operation and longevity.
6. 6

   Install the new blower motor control module
   Position the new module in the same orientation as the old one, aligning any mounting tabs or flanges with the HVAC housing. Ensure the cooling fins are positioned to receive adequate airflow from the blower motor. Press the module into position against the mounting surface.
7. 7

   Install the mounting fasteners
   Install the mounting screws and tighten them securely. Do not overtighten, as you are threading into plastic or thin metal housing material. Tighten the screws evenly to ensure good contact between the module and housing for heat dissipation.
8. 8

   Reconnect the electrical connector
   Push the electrical connector onto the new blower motor control module until you hear or feel the locking tab click into place. Verify the connector is fully seated by gently pulling on the connector body (not the wires). The connector should not come off.
9. 9

   Reconnect the battery
   Reconnect the negative battery terminal and tighten the battery clamp bolt to specification.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Ensure the electrical connector is fully locked onto the module
2. Verify all mounting fasteners are secure but not overtightened
3. Confirm the module has adequate clearance and is positioned for proper cooling airflow

Verification

• Turn the ignition to the ON position (engine may remain off)
• Test all blower motor speed settings (Low, Medium-Low, Medium-High, High) to verify proper operation at each setting
• Listen for smooth motor operation without unusual noise or hesitation when changing speeds
• Verify airflow volume increases appropriately with each higher speed setting
• If equipped with air conditioning, test blower operation with A/C on and off to ensure consistent performance
• Check that the blower motor does not run continuously at high speed regardless of switch position, which would indicate a faulty module or poor connection

Related trouble codes on this vehicle

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

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