That is a typical sign that the blower resistor has gone faulty
Full cold, medium fan, recirculation or max settingFull cold, medium fan, recirculation or max setting
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.
A 4-speed fan switch typically has settings for low, medium-low, medium-high, and high speeds. These settings can be adjusted by turning the switch to the desired speed level. The fan speed will change accordingly based on the selected setting.
The 2004 Chevrolet trailblazer air conditioning fan switch has three settings. The switch can malfunction, and only work in the high setting.
It could be due to a faulty resistor in the blower motor circuit. The resistor regulates the speed of the blower motor, and if it malfunctions, the high speed setting may not work properly. It would be best to have a mechanic inspect and replace the resistor if necessary.
This fan has three speed settings, low, medium and high.
Heater is not working in a 2002 ford foucs only work when fan setting is place in?
Blower motor resistor...around $25 on eBay
The GE Spacemaker Over the Range Microwave Oven has a two speed fan, and a light with one setting.
The high-speed setting on a heater fan may not work due to a faulty resistor, a malfunctioning fan switch, or a problem with the fan motor. It is recommended to have the issue diagnosed by a professional technician to determine the exact cause and appropriate solution.
Resistors control the speed of the AC/Heater fan. These resistors are switched on and off in various combinations to create the different fan speeds. When the resistors burn out your fan will only work on the "HI" setting. The "HI" setting doesn't use any of the resistors and that's why it works. These resistors are near the blower and the blower is beneath the dashboard on the pasenger side. Just have to located resistors now.
Try replace the resistor. It's locate pass.side under dash by fan blower with one plug and two bolts.