heater fan rattle - newish Mazda Miata

[ragtophardtop]

I've got a rattle in my heater fan when it's running around 50% power, it goes away at lower and higher speeds. I stuck my head under and listened, and I'm sure its coming from the fan unit under the glovebox.

Before I take it out and start hunting for the problem, does anyone have experience or advice they'd like to share? It sounds like the fan has a slight wobble that's evident at 50% speed, but not at others. It does not sound like a leaf or debris.

 

[mk378]

Very common for mice to get into the ductwork. Besides leaving debris, they also like to chew away parts of the blower wheel, throwing it out of balance.

Start by pulling the cabin filter if it has one, you will see a hole in it if mice came through. In a lot of cases the motor and wheel can be removed without major disassembly.

 

[ragtophardtop]

Thanks! No cabin filter. I'll pull it and update. This one was garaged and covered when not in use and is in pristine condition, so I'm hoping it's not an issue with mice.

 

[bdcardinal]

We have replaced a fair amount of those, even more than one on the same vehicle, for critters getting inside there. Just be lucky you didn't start the car with the little fellow in there.