- 2022 2.5GT
Modern heaters don’t work with the same “ram air” effect as the old designs did and with the blower fan off, virtually no air will find it’s way through the cabin filter and the labyrinth of passageways into the car. For that reason, the fan is blowing constantly the whole time the car is running. They’re not brushless motors, they are conventional brushed motors and they have a lifespan. It’s amazing how many owners interfere with the settings when all they need to do is set a comfortable temperature and leave it in “auto” and the computer will do the rest including set it back to idle when not needed. That’s instead of roaring away to no good end and reducing the life of the motor. When a motor goes on the blink, it’s invariably the brushes which lose tension and start to stick as they wear out. I tend to pull them to bits and put new brushes in but other than that it’s not that expensive and only about 20 minutes to change the motor which sits inverted above the passengers feet. Finding a fault is easy if it’s displaying it but if you take a working fan into a dealer it’s bloody awkward to find other than tapping things and wriggling wiring connections so it’s easy to be critical about it. If it doesn’t work, plugging a new fan or measuring voltage at the fan plug takes a few seconds. If there’s juice it’s the fan, if there isn’t it’s the control system (usually the control module). As always the conspiracy theories pop up - “there’s more to this than meets the eye” or “mazda are hiding something”. There isn’t. It’s a fan that never stops working from the day the car rolls out of the dealership and when you consider how many millions of cubic feet of air it pumps over several years, it’s amazing it lasts as long as it does. Well done to the OP for taking a punt on the $120 fan, it’s the bit with moving parts and the control unit is solid state so it’s where I’d start every time. For everyone else, if your car is over about 3-5 years, that’s where I’d start on yours too. That little motor has got wearing parts in it.