Four Seasons 3666N A/C Compressor Kit - Front

Four Seasons PAC-Kit w/ New Compressor 3666N

Four Seasons 3666N is a PAC-Kit with a new compressor for front A/C service on select GM and Saab applications. It is built for vehicles equipped with a TRSA12B compressor, with specific 2004 fitments for TRSA09K compressor applications and no rear A/C.

Key Features

• Brand: Four Seasons
• Part number: 3666N
• Category: A/C compressor kit
• PAC-Kit with new compressor for front HVAC service
• Application-specific fitment for select Chevrolet Trailblazer, GMC Envoy, GMC Envoy XL, GMC Envoy XUV, and Saab 9-7x models
• Includes fitment notes for compressor type, rear A/C configuration, accumulator, orifice, flush, and oil references

Vehicle Fitment

• Fits 2006-2009 Chevrolet Trailblazer, front, w/ TRSA12B Compressor; w/o Rear AC.
• Fits 2005-2009 GMC Envoy, front, w/ TRSA12B Compressor; w/o Rear AC.
• Fits 2005-2009 Saab 9-7x, front, w/ TRSA12B Compressor; w/o Rear AC.
• Fits 2004-2006 Chevrolet Trailblazer EXT, front, w/ TRSA12B Compressor; w/o Rear AC.
• Fits 2004-2006 GMC Envoy XL, front, w/ TRSA12B Compressor; w/o Rear AC.
• Fits 2004-2005 GMC Envoy XUV, front, w/ TRSA12B Compressor; w/o Rear AC.
• Fits 2004 Chevrolet Trailblazer EXT, front, w/ TRSA09K Compressor; w/o Rear AC.
• Fits 2004 GMC Envoy XL, front, w/ TRSA09K Compressor; w/o Rear AC.
• Fits 2004 GMC Envoy XUV, front, w/ TRSA09K Compressor; w/o Rear AC.

What It Helps Address

• Loss of cabin cooling from compressor wear or failure
• Weak or inconsistent A/C performance in the front system
• Noisy compressor operation tied to internal damage
• System contamination concerns after compressor replacement
• Service needs on Trailblazer, Envoy, and 9-7x front A/C systems

Installation Notes

Verify the compressor type before ordering: TRSA12B is listed for most applications, while select 2004 Trailblazer EXT, Envoy XL, and Envoy XUV models use TRSA09K. This part number, 3666N, is specified for front systems without rear A/C. Follow proper evacuation, flushing, oil service, and component replacement procedures during A/C repair.

Quality Assurance

Four Seasons 3666N is a PAC-Kit w/ New Compressor built for application-specific HVAC service. This part cross-references 78548 and 83222 for the same application.