Blower Fan Motor Noise

The sounds happen in cold or humid weather and especially when hitting bumps in the road or slamming on the brakes.

Blower fan motor noise.

There is more than one possible cause for a noisy air conditioner. Sometimes this noise is not due to a blower motor problem but occurs because debris is caught inside the blower assembly. However if the motor doesn t run at all chances are it has a bad temp sensor or speed switch. Blower motor mount squirrel cage plenum filter too small or the furnace itself vibrating.

Quiet a loud blower motor. The blower motor is a small rotary motor that drives a fan sitting behind your vents pushing hot or cold air through them at varying speeds depending on your selection. Even though it s in a housing it lives in the engine compartment so it s not unheard of for foreign objects to get sucked into and wrapped around or caught in the fan. There s a rattling or buzzing noise coming from the condenser unit when the fan is turned on.

If your blower runs but is noisy buy just the motor fan assembly. This debris often works its way down into the hvac system from the vent opening under your windshield wipers at the base of your windshield. During blower operation this debris causes the blower motor to be noisy. Sometimes during blower motor operation you might hear excessive noise.

Humming sound a humming sound is one of the most common blower motor noises reported by home owners. If you hear a loud rattling noise it could be a minor issue like loose stones or debris that s caught in the condensing unit. The sounds happen less when blower is on higher settings and all the time on lower speeds. Once it is safe to touch examine the motor and look for any obvious signs of wear or breakage.

If your interior ac heat fan blower motor is making noise like a card in a bicycle spoke then you probably just need to clean. In that case buy a complete kit. Squealing and screeching sounds coming from beneath the passenger side dash when the a c heat blower motor is on. Remove the old fireplace air blower.

Your first step after noticing this sound should be to turn off your furnace s motor and let it cool down.