u need a new blower motor
Heater blower resistor is what controls the low medium high speeds...
the blower resistor controls the fan speeds
Figured it out...the blend door actuator was not fully seated when I replaced it.
Most likely the Blower Motor Resistor.
Blower motor speed resistor is partially burned out.
If you have 12 volts at the blower, And the blower runs when it is straight wired. The blower switch runs through a resistor that allows the blower to run in low, medium-low, medium-high. Find and check this resistor. Most of the time it is located on the passenger side of the firewall.
When the fan is on high it does not run through the blower motor resistor. The low speeds don't work because the blower motor resistor is bad.
That is a typical sign that the blower resistor has gone faulty
The blower motor resister for an Acura Legend drops the voltage to the blower motor. This is what allows the motor to run slower for the medium and low settings.
More than likely the blower resistor is bad....I recently ran into this problem in my 91 Vette...Hope this helps!
propably need to replace the blower control switch/resistor
If the low and medium speeds of your fan are not working and only the high speed is working, then it is probably the resistor fan control module. This unit will have to be replaced. It is generally located underneath the dashboard on the passenger side. Locate the blower motor and trace back the two power leads from the blower motor. They will terminate at the resistor module. The resistor module is a series of resistors that controls the amount of current flowing into the fan motor. On low speed settings, the current flows though all the resistors and as you increase the fan speed, resistors are switched out until eventually at the highest setting the complete resistor network is switched out. That is why you end up with only high blower fan speeds when the resistor module becomes defective.