The blower motor is the fan that pushes air through your vents, and the climate controls and blend door actuators decide where that air goes and how warm it is. AutoTech Clinic repairs weak airflow, dead fan speeds and failed climate controls at our Dearborn shop, usually the same day.
If only the highest fan speed works, the cause is almost always the blower motor resistor. That is one of the most common and least expensive climate repairs there is.
- How Long
- About 1 to 3 hours for most blower motors and resistors.
- Same Day
- Usually finished the same day.
- Vehicles
- Foreign and domestic, cars through trucks.
Signs You Need Blower Motor and Climate Controls
- Only the highest fan speed works
- No airflow from the vents on any setting
- Airflow is weak on all speeds even with a new cabin filter
- A squeal, rattle or ticking from behind the glove box
- Air comes out of the wrong vents regardless of the setting
- Clicking from behind the dash when you change temperature or mode
What We Do
- 01
Check the Cabin Air Filter
A clogged cabin filter is the cheapest cause of weak airflow and the one we check first. On many cars it is behind the glove box and takes minutes.
- 02
Test the Blower Circuit
We check for power and ground at the motor, then test the resistor or control module that sets the speeds.
- 03
Listen for Debris
Leaves, acorns and nesting material in the blower housing cause a ticking or rattling and restrict airflow. We remove the motor and clean the housing.
- 04
Command the Actuators
We use the scan tool to command each blend and mode door and listen for the actuator responding, which identifies a failed one quickly.
- 05
Repair and Retest
After the repair we test every fan speed and every mode and temperature setting before the car goes back.
Only High Speed Works: Here Is Why
On most vehicles the lower fan speeds are produced by sending current through a resistor pack that drops voltage. Top speed bypasses the resistor and feeds the motor directly. So when the resistor burns out, every speed dies except the highest one.
There is a second lesson in that. Resistors usually burn out because the blower motor is drawing too much current as its bearings wear. If we replace a resistor on a motor that is dragging, you will be back. We check motor current draw as part of the job.
Cabin Air Filters Get Forgotten
Most vehicles built in the last twenty years have a cabin air filter, and a great many have never had it changed. A filter packed with leaves and dust chokes airflow on every setting and makes the blower work harder.
We check it at every service. It is an inexpensive part, it takes minutes on most cars, and it is often the entire fix for weak airflow and a musty smell.
What Affects the Cost
We quote your vehicle specifically after inspecting it, because these are the things that move the number up or down:
- Whether the fault is the motor, the resistor, a control module or an actuator
- Access, since some blower motors are behind the glove box and others under the dash
- Vehicles with automatic climate control, which use a power module rather than a resistor
- How many actuators are involved on a dual or triple zone system
- A cabin air filter replacement at the same time
Call (313) 277-7200 with your year, make and model and we will tell you what to expect before you come in.
Why AutoTech Clinic
AAA Approved
An inspected facility that has to meet AAA standards for equipment and training.
Photos First
You see what we found and approve the price before anything is taken apart.
Same-Day Service
Parts on hand for the vehicles we see most, so you are not waiting on a delivery.