Semi-Truck HVAC Climate Control Unit Failure | UpFix

Why Isn’t My Truck’s A/C or Heater Working?

When the HVAC system stops responding—no fan, no temperature control, or no airflow—the problem is often the electronic climate control unit. This module manages temperature sensors, blower speed, and actuator motors.

With constant heat cycles and vibration, internal solder joints or potentiometers fail, causing erratic temperature regulation or total loss of function.

Common HVAC Control Symptoms

• Fan doesn’t blow or only works on one speed

• Temperature stuck hot or cold

• Buttons or dials unresponsive

• A/C light on but compressor doesn’t engage

Why Repair Is Smarter

Replacement HVAC control units can be difficult to source and require calibration. UpFix repairs your existing control unit, preserving compatibility with your truck’s wiring and sensors.

UpFix HVAC Repair Process

1. Test fan control and actuator communication circuits

2. Replace damaged potentiometers, transistors, or drivers

3. Verify temperature response and mode selection

4. Bench test all fan speed and blend-door outputs

Supported Brands

Freightliner, Volvo, International, Kenworth, Peterbilt, Mack and others.

Get your truck back on the road and keep your costs low.
Send your part to UpFix for professional testing and repair.
We’ll restore it to like-new condition, save you up to 80% compared to buying new, and make it plug-and-play ready when returned.