Back to all

Such a Little Part (Climate Control Resistor)

December 1, 2024

You expect your heater/air conditioner to work like it should.  You have a control for temperature and one for fan speed.  You even have a control for what vents the air comes out of. 

Don't be surprised one day if your blower fan develops a mind of its own and starts going crazy.  Most of the time, you may find that it starts blowing at full speed, and nothing you do to try to control it does any good.  This is what may be happening.

Your blower motor has an electronic component called a resistor.  It does what its name says; it offers resistance.  When you want the fan to run more slowly, you turn the fan speed down.  That resistor accomplishes that by turning its resistance up.  When the resistor fails, the power has nothing to slow it and the fan speeds up. 

It's a small part and can fail due to age or corrosion.  It's usually not an expensive part, either, but it's often found in a location that's not that easy for the technician to get to.  That means labor costs will vary depending on the design of your vehicle. 

Occasionally, a faulty resistor can cause the blower motor not to work at all or only partially come on.  But other things can cause that as well, such as a faulty fan switch or vent control. 

This is where a technician's training comes in.  Special equipment can track down precisely where the issue is so you can be assured the correct part is being replaced.

It's just not pleasant when the blower motor isn't following orders.  Have your service facility check it out so you can be the blower's boss, like it should be. 

Charlie's Fast Lube Dexter
414 N 1 Mile Rd.
Dexter, Missouri 63841
573-614-7886
http://charliesfastlubedexter.com

Need Service?

Request a Quote

More articles from Charlie's Fast Lube Dexter

Wired! (Battery Cable Service)

January 25, 2026

Colder weather brings out the worst in a vehicle's battery. On a very cold day, you may have experienced that your engine cranks slowly when starting. But while it may be the battery itself, it may also be the parts that transfer the power to other the other electrical components, the battery c... More

Cool Running (Water Pump)

January 18, 2026

Your vehicle is like you in a way. When it gets hot, it needs to be cooled down. And one of the key parts to keeping it cool is the water pump. Now, that's a bit of a misnomer. It IS a pump, but it's pumping coolant, not pure water. Cooling off your engine is vital since it builds up heat whe... More

I Had No Idea! (Four Things You Didn't Know About Vehicles)

January 11, 2026

Bet you didn't know: Some of the earliest rearview mirrors were marketed as "Cop Spotters" so drivers would know when police were following them. Who wants a ticket, anyway? According to eBay Motors, Elmer Berger first patented a rearview mirror that was mounted on the front fenders, on the spare... More