Estimates last updated October 16, 2025

2008 Mercedes-Benz SL550 HVAC Blend Door Actuator Replacement Cost

The average cost for a 2008 Mercedes-Benz SL550 HVAC Blend Door Actuator Replacement is between $958 and $1,363.

Labor costs are estimated between $866 and $1,271 while parts are typically priced around $92.
This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.

HVAC Blend Door Actuator Replacement

What is a blend door actuator?

In a vehicle's heating and cooling system, the blend door actuators help control the air temperature from the vents, and direct air to selected vents.

How does the blend door actuator work?

To blow heat into the cabin, the blower motor sends air through the heater core and on through the dash vents. But when heat is not desired, the blend door actuators direct that airflow away from the heater core. There are also actuators to direct air to the dash vents, floor vents and windshield vents depending which setting is selected.

What are the symptoms related to a bad blend door actuator?

The symptoms of a bad blend door actuator include a lack of heat or air conditioning, or failure of air to blow through some or all of the vents. The actuator motors may also make a noise if they've failed, but this isn't always the case.

Can I drive with a blend door actuator problem?

Driving with a bad blend door actuator may not be comfortable, but it won't hurt the vehicle.

How often do blend door actuators need to be replaced?

Blend door actuators fail frequently on some vehicles, but not in others. So, the rate of failure will depend on the vehicle make, model and year.

How are blend door actuator issues diagnosed?

Mercedes-Benz HVAC Blend Door Actuator Replacement Cost Estimates

The average cost for a HVAC Blend Door Actuator Replacement is between $958 and $1,363 but can vary from car to car.

Mercedes-Benz SL550 HVAC Blend Door Actuator Replacement Cost by Year

The average cost for a Mercedes-Benz SL550 HVAC Blend Door Actuator Replacement is between $958 and $1,363 but can vary from car to car.

2012 Mercedes-Benz SL550

$177-$217

2011 Mercedes-Benz SL550

$177-$217

2009 Mercedes-Benz SL550

$958-$1,363

2008 Mercedes-Benz SL550

$958-$1,363

2007 Mercedes-Benz SL550

$958-$1,363

HVAC Blend Door Actuator Replacement

Jump to:Commonly associated repairs Cost estimates by vehicle Cost estimates by year

What is a blend door actuator?

In a vehicle's heating and cooling system, the blend door actuators help control the air temperature from the vents, and direct air to selected vents.

How does the blend door actuator work?

What are the symptoms related to a bad blend door actuator?

Can I drive with a blend door actuator problem?

Driving with a bad blend door actuator may not be comfortable, but it won't hurt the vehicle.

How often do blend door actuators need to be replaced?

Blend door actuators fail frequently on some vehicles, but not in others. So, the rate of failure will depend on the vehicle make, model and year.

How are blend door actuator issues diagnosed?

The technician will test each vent position and temperature range. The amount of air and its temperature will be noted for each setting. If there's no change between settings, the blend doors are a strong possibility. When these components are suspected, testing the circuit and observing them while they're working are the only ways to test them. The electrical wires or vacuum lines will be inspected to ensure the proper amount of power is being delivered. From there, the parts can be bench tested to pin down the problem.

How is a blend door actuator replaced?

Replacement procedures vary by vehicle. Some actuators will be easy to access, but others will require removing the airbags and dismantling the dashboard or parts of it. Most modern vehicles, especially those with dual climate control features and rear passenger air options, can have several blend doors and actuators.

RepairPal recommendations for blend door actuator issues

We don't recommend using DIY universal blend door correction kits, as these kits involve cutting into the HVAC ducts and replacing OEM components with generic components.

Can I replace the blend door actuator myself?

Because of the amount of disassembly that may be required, this repair is usually best left to a professional mechanic. Removing airbags and other dashboard components can be dangerous, and can leave car safety systems compromised if not handled correctly.