I have 1995 Cutlass with the Electronic Climate Control. One day the heat/AC system worked fine, but the next time I went to use it, I discovered that when I run the heater/AC fan at medium to high speed, I get a loud vibration/rumbling sound coming from inside the dash.
At low fan speed, I get air flowing through the vents. But as I start to increase the fan speed, the virbration/rumbling sound gradually gets louder, but there is no increase in air flow out of the vents.
Thanks in advance for any ideas on this..