You didn't mention what year S10 Blazer you have but, the blower motor speed resistor can be found under the hood, on the passenger side of the firewall, close to the blower motor.
try a blower motor resistor
The blower resistor gets overheated and burns out usually because the blower motor is failing also.
The fuse. The blower motor speed resistor. The blower motor relay. The blower motor switch. Check for power at the blower motor connection.
The high speed relay for the blower motor would be found under the hood, on the passenger side of the firewall, close to the blower motor speed resistor.
Should be behind the glove box. The blower motor speed resistor is located under the hood, on the firewall, passenger side, close to the blower motor.
probably the blower motor resistor
Ain't no fixin it, you have to replace it with a new one.
The rear blower motor resistor location for a 2003 Chevy Trailblazer Ext LT is beneath the passenger side of the dash.
Under the hood, passengers side firewall, close to the blower motor.
They get noisy, squeal and vibrate. Also if you keep burning out the blower motor resistor, that is a sign the blower motor is on its way out.
if you have a 2003 Chevy Trail blazer and you need to replace the resistor for the rear blower, the one under the passenger side dash is the one that controls the front and rear blower.
Under the hood, on the firewall, passenger side, close to the blower motor. If the blower motor resistor is burned out, you should still have the high speed function.