blower motor
 

My 01 protege has a blower motor that likes to speed up and slow down all by itself--not significantly but enough that you notice. The dealer says every thing checks out fine. I have replaced the battery and checked the alternator so I am guesing the blower motor or switch is starting to go. Is this a problem area for these vehicles?

Mine has done it since the say I got it...Read your owners manual, I think it says something in there about it.