Sounds like vents are in open position where it passes through based on speed with or without fan on
Jammed blend door or blockage in the ducts if you mean to say air isn't blowing through at all.
first thing to check is the fuse
The electric heating elements are probably turned on.
You need to check the vacuum lines for the a/c system for leaks, breaks and loose ones first.......
I have a 99 Ford F250 super duty. When I turn on the fan to the heater and AC I can hear air moving in to the vents. No air moves out of the vent on any setting. It is like all vents are closed. what could be the problem. I have replaced the switch. I check the blower motor.
Front heater core is in the dash, the rear heater core is all the way in the back of the vehicle. If you have steam coming out of the dash vents, the front HC is leaking. If you have steam coming out of the rear heater vents, then the rear core is leaking.
After Unplugging your ac check the opening of the front with something that you can slide inside the opening like a tooth brush. Do it gently. There is a blower behind the opening. At times a lot of dust particles get stuck in the blower ( its like a long roller ). All you have to do is clean this blower with the brush. If you could post the brand of your Ac, Type and capacity, It will be more helpful. Generally its not difficult after you have seen it being done once. Tell me if it works.
You have a vacuum leak. Usually find the hard thin vacuum line that runs from L/H top of the engine acroos the front and over to th eR/H fender broken. But it could be from any part of the vacuum system.
Check for a broken vacuum line by the battery. These lines get brittle and break with age.
if the resistor isn't bad then you should have all speeds, temperature, and levels for the vents working. if your not getting anything blowing threw the vents at all give the blower moter a couple taps and if that doesnt work then its 99% likely the blower motor is blown
The fan blows air out the front vents and doesn't change to floor, defrost or bi-level. I can adjust the temp and fan speed. A week before I noticed this, the HVAC display blacked out until I restarted. I have the exact same issue with my 2004 Pacifica. In my case, however, a week before, it was switching from air blowing to the floor, then the center vents then the defroster all by itself without my input. Finally, it rested on the center vents and now that's only where air blows from. If anyone knows the answer, please email me at rose11422@gmail.com