Q: How do I know if it's my blower motor resistor or the resistor switch that's not working?

asked by on

My A/C and my heat won't turn work and nothing blows out and it doesn't seem to defrost really well when it's cold. I'll turn the switch and the green light says its on but nothing seems to happen. I took it to auto zone they said my blower motor is fine and could be either the resistor or switch, but how do I tell which one I need?

My car has 100100 miles.
My car's transmission is unknown to me.

The referenced parts are tested with an ohmmeter. The resistor block must have a specified resistance across each element on the block. However, if any resistors are open (infinite resistance), the block is just condemned and replaced automatically. Occasionally, you might be able to see that the resistor block is obviously broken (elements are open). Switches are tested using an ohmmeter or continuity tester. There are other electrical components, and wiring, in the system that can cause it not to work. If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a blower motor diagnostic and the responding mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. How do I know if it's my blower motor resistor or the resistor switch that's not working?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My heater makes a really loud noise when its on.

The level of refrigerant in the air conditioning system would not affect the noise level of the blower motor. If you replaced the motor with an aftermarket (non OEM) motor that could create an issue in terms of the quality...

Q: Where is the location of the thermostatic fan switch?

Hi there. The thermostatic fan switch is located under the hood, in the center rear engine area, below valve cover, and is mounted on lower driver side of engine block. The thermostatic fan switch turns on the electric fans when...

Q: Q: car wont stay running

If you say there is an "alarming" sound when it starts, then I would only suggest you have a proper diagnosis done. By doing so you'll be able to find the cause before you try and run it any more....

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.