BT5-42021 Heavy-Duty A/C Compressor – TM-08HD, 12V, 2-Groove

The BT5-42021 A/C compressor is built for mobile air-conditioning systems that require steady cooling and dependable operation. Because it uses the proven TM-08HD compressor platform, it provides consistent refrigerant flow while maintaining compact size and efficient output.

In addition, the ear-mount configuration allows flexible installation across a wide range of brackets. As a result, this compressor works well in retrofit, replacement, and custom HVAC builds.

Furthermore, the vertical fitting layout with #8 and #10 male insert O-ring ports supports clean hose routing and reliable sealing. Therefore, leak risk is reduced while long-term system performance improves.

The BT5-42021 operates on a 12-volt electrical system and uses a 135 mm, 2-groove clutch designed for dual 1/2-inch belt drives. Because of its bidirectional rotation capability, it supports both CW and CCW rotation, adding flexibility across multiple applications.

Specifications

General

• BTRAC Part Number: BT5-42021

• Compressor Model: TM-08HD

• Application Type: Multi-Fit

• Refrigerant Type: R134a

Mounting & Head

• Mounting Type: Ear Mount

• Fitting Port Position: Vertical

• Fitting Style: Male Insert O-Ring

• Fitting Sizes: #8 and #10

Clutch & Drive

• Clutch Diameter: 135 mm

• Clutch Grooves: 2

• Belt Type: Two 1/2″ belts

• Shaft Type: Splined shaft

Electrical

• Voltage: 12 V

• Wire Type: 1-Wire Bullet

• Rotation: CW / CCW

Internal

• Number of Cylinders: 6

• Compressor Displacement: 5.2 cu.in.

• Oil Type: PAG 46

• Diode Protection: None

Service Parts

• Replacement Clutch Assembly: NSS

• Replacement Head Assembly: NSS

• O-Ring #1: 0013

• O-Ring #2: 0015

Cross Reference Numbers

• MEI: 5934

• CoolStar / MEI: 340-1120

• ICE: 2521136

• Seltec / Valeo: 435-52021, 488-42021

• Valeo / Seltec: 10052021, 100-52021

• Truck Air / MEI: 03-3100

Applications & Notes

• Multi-fit mobile HVAC systems

• Light to medium-duty trucks and equipment

• Custom and retrofit A/C installations

However, always verify mounting configuration, belt alignment, refrigerant compatibility, and electrical requirements before installation to ensure proper system performance.