Manage rear blower fan speed with the Four Seasons HVAC Blower Motor Resistor, part number 20630. It fits many vehicles, among them the 2002-2006 Chevrolet Trailblazer, 2002-2006 GMC Envoy and 2003-2008 Isuzu Ascender, and is a direct-fit replacement for the listed applications. This rear-position resistor is also cataloged under the switch part type, and it sets how fast the rear HVAC blower runs at each fan setting.
A blower motor resistor varies the electrical resistance in the blower motor circuit so the fan can run at the different speed settings chosen on the climate controls. Four Seasons engineers and tests its products for trouble-free operation, drawing on more than 50 years of mobile A/C experience.
- Vehicle-specific applications: built for the listed vehicles rather than as a universal-fit part.
- Precision engineered: designed and tested by Four Seasons for its rear HVAC blower application.
- OE style connectors: the connector style follows the original equipment design.
A rear blower that runs on only some speed settings, or not at all, is a common sign this part may need replacing. If a failed resistor is the cause, this unit replaces it. Diagnose the circuit first, because the blower motor, control switch or wiring can cause similar symptoms. See the "Vehicles it fits" section for the full list of fitting vehicles.
Interchange: 1572813 · 4P1602 · 88892976 · 1712121 · 1713370 · ACD1572813 · 8888929760 · A06980 · MT17733 · JA1724
This part cross-references / interchanges with the following part numbers:
1572813, 4P1602, 20630, 88892976, 1712121, 1713370, ACD1572813, 8888929760, A06980, MT17733, JA1724
Frequently Asked Questions
Is this the right Trailblazer switch for the rear blower?
Yes. It is a rear HVAC blower motor resistor, listed under the switch part type, and it fits the 2002-2006 Chevrolet Trailblazer. Check the "Vehicles it fits" section to confirm your exact vehicle.
What does a blower motor resistor do?
It varies the electrical resistance in the blower motor circuit so the rear fan can run at the different speed settings selected on the HVAC controls.
What are signs the blower motor resistor may need replacing?
A rear blower that runs on only some speed settings, or not at all, can be a sign. The motor, control switch or wiring can cause similar symptoms, so diagnose the circuit before replacing.
Does it use OE style connectors?
Yes. Four Seasons builds this resistor with OE style connectors for its vehicle-specific applications.
Is this also the Envoy switch for the rear blower?
It is cataloged as the rear HVAC blower motor resistor for the 2002-2006 GMC Envoy and the 2003-2008 Isuzu Ascender. Check the "Vehicles it fits" section to confirm your exact vehicle.
