Earatic heater motor speed 97 Blazer

[urickmic]

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

[brusk1]

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.

[BlazerLT]

Sounds like the blower motor is almost gone.

[Mikado14]

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