sounds like there is short in the flux condenser that senses the pressure change in the differing temperatures KansasCity Computers
it's a problem with the blower motor resistor
As for why it blows only on the high speed you most likely will have a bad blower resister and for the noise, it could be a bad blower motor, bad blower wheel or trash that is stuck in the blower wheel or housing.......
The blower is common to hot and cold air. If it is only cold air that is a problem, then the problem is not the blower motor. The blower motor is actually in the engine compartment, passenger side at the firewall.
Typically a relay or resistor. But could be a blower switch or blower motor problem.
Blows on #4 only? I would replace the resistor. #4 speed by-passes the resistor.
Replace the blower motor also.
blower motor resistor thermal limiter is blown. Replace the blower motor resistor.
Short in the circuit somewhere. Try unplugging the blower motor, closing the circuit with a test lead or test light, and seeing if it blows then. If not, the problem would seem to be in the blower motor itself.
It will be located somewhere in the path of the air that the blower motor blows.
A glass blower is a person that blows glass.
Your heater coil is bad.
Somewhere in the path of the air that the rear blower motor blows