That’s a good question because it happens so often. There is a motor about one foot down from your dash and about one foot back from your center console. Here lies the blower motor, the bane of too many 240 and 740 drivers.
The motor has two nautilus-shell looking blades on each side that blow air coming from the little grills at the top of your hood or recycled from inside the cabin. The motor shafts of the motor are exposed to moisture in the air and after 20+ years they start to corrode. The corrosion grows along the shafts and eventually works its way into the motor area itself. The parts in the motor need to be clean in order to operate properly, and when it’s not, that’s when you start hearing the squeal.
Eventually the corrosion on the motor will get so bad the motor will completely cease. There is only so much space between the pieces in the motor, completely locking it up. Unfortunately, no servicing can really happen for the motor other than completely replacing it.
A blower motor replacement job is tedious, to say the least. You must move a lot of dash and center console pieces to even get to the shrouds housing the motor. There are different tricks you can check out by googling the steps, but the instructions don’t really help the job be any less of a major project. Seriously, check it out.
And on cars 1984 and older, newer style blower motors don’t match the holes perfectly for the brackets on the car and you have to cut/grind the brackets down a bit. It’s a pain and if you don’t do it correctly, the motor will be off camber and the motor blades will hit the housing, making a different terrible sound.
Needless to say, it’s a rough job but at least you know what’s going on with it. When you are looking to purchase your next Volvo, if it’s a 240 or 740, keep in mind if the blower motor doesn’t work you’re going to need to have it serviced before it starts getting cold… because you can only drive with the front windows cracked for so long to defog your windshield. I personally have gone through a few seasons like this, but I have really warm gloves and love the rain.
r-sportinternational.com