97 Blazer
Heater motor sometimes blows hard sometimes hardly
without any changes in the rotery switch position
any ideas at to the problem it's fricken cold here in wisconsin
this morning 6 tomorrow -5
Thanks for the help
Urickmic

Could be a faulty blower motor resistor or your blower motor is going out.

I had a similar issue this summer when my heater core leaked and I lost fan control (I guess the coolant fouled my blower motor resistor 94 Blazer)... In the interim, I just unplugged the blower motor resistor which left me with high speed fan only.

Sounds like the blower motor is almost gone.

What LT said, sounds like the brushes are worn down and you are getting varying spring tension. Change the blower.