A clicking noise behind the dash and air stuck on one temperature is a blend door actuator, one of the most common failures on GM, Ford, and Chrysler vehicles. No heat with a hot engine is usually a clogged heater core, a stuck valve, or air in the system. We diagnose which and fix it.
Signs you need heater & blend door repair
- Clicking or knocking from behind the dash
- Air won't switch between hot and cold
- Air only from defrost or floor vents
- No heat even when the engine is warm
- Sweet smell inside the cabin (heater core leak)
What we do on site
- Scan the HVAC module for actuator codes
- Test heater hose temperatures to diagnose core flow
- Replace the blend, mode, or recirculation actuator
- Flush the heater core if clogged, replace hoses or valve as needed
- Recalibrate the HVAC system
Doing this in a driveway
Actuators and flushes are mobile. Heater core replacement requires removing the dash and is not something we do in a driveway.
Parts we use
Blend door actuator, mode door actuator, heater hoses, heater control valve, coolant.
Pricing: Actuators are moderate depending on access; core flushes are inexpensive; heater core replacement is a shop job. Every job is quoted in writing before we start, and there's no upsell — how our pricing works.
FAQ
Heater & Blend Door Repair: common questions
Why does my truck click behind the dash when I start it?
A blend door actuator with stripped gears. It cycles at start-up, hits the stripped section, and clicks. Very common on Silverados, F-150s, and Rams.