The blower works with the AC because it helps circulate the cool air produced by the air conditioning system. However, it may not work with the heat because there could be an issue with the heating system, such as a malfunctioning heater core or a faulty thermostat.
sounds like your blower motor went bad,does it work on heater heat.
I would look into the blower motor resistor module
Blown fuse, bad motor, bad blower motor switch, or a defective Blower Motor Resistor Pack.
Why does my 99 silverado have no heat and the ac fuses look good and blower motot works great
if all speeds do not work id say is a fuse, but if you just dropped one or two speeds. replace the blower motor resister. sells for $60.00 at the dealer.
Assuming that by "high," "low," and "medium" you are referring to HVAC blower fan speed and that this happens with heat as well as with AC: Replace the blower resistor. It's no good.
it is the moter that spins the fan that blows your heat or ac out of your vents
I would start by checking the fuse, the relay, and the connector on the blower itself.
There should be only one blower to move the air. The unit will have a coil for cooling and a heat exchanger.
You'll need to replace the blower motor resistor. ya gotta bad switch, good luck
Did you check with OBD ? Maybe the problem with AC clutch relay. I have same problem with my 1993 Grand Cherokee Limited, and I bring to my mechanic and fix, because the connection on AC clutch relay relist. Hope can help
faulty blower motor resistor