I have a 99 Olds Intrigue. When I turn on the fan (any temp) the fan makes what could be described as a loud screeching noise. The stronger I set the fan speed, the louder the noise. The noise will stop after approx 10 seconds when the fan is on high. Any answers. Also, this may be related, the fans router system, whether it blows to the defrost, console, or foot level doesn’t work. It just blows everywhere.
The load screeching is a dry fan bearing, it’s easy enough to change the fan on an Intrigue and you may be lucky enough to get away with lubricating the bearing - use light low odour oil otherwise your car will smell like a ships engine room everytime you use the heater.
The router system is operated by vacuum tubes, these could either be disconnected at either end or the actuator could be jammed, hard to tell without looking at it. If you have a vacuum pump you can test the vacuum circuit. Small hand pumps are about $20.
This is called the GM fan syndrome and most GMs will get it at some point. Only thing to do is 1) live with it, 2) replace the blower motor, or 3) take the blower apart and oil the bearings. It’ll get better as the weather warms.
And this is called total optimism 