It's likely there is a leaky air duct at some point behind the dash.
Here is the solution. Disconnect the negative terminal on the battery for a least five minutes. Open BOTH drivers and passenger FRONT doors and leave them open. Re-connect the negative battery cable. Shut doors and start the car. Your air should work fine. This ridiculous procedure re-sets the module that controls the A/C & heat distribution. Only GM engineers would come up with this one!!
The 1998 Oldsmobile Intrigue turn signal flasher control module is below the dashboard on the drivers side of the passenger compartment. The signal flasher control module should be labeled as such.
Have you tried pressing the cruise control button on the dash?
It is a half-inch blackish bulb next to the air vent on top of the dash. Don't put your hat over it, or your lights will stay on all the time.
UNDER THE COIL PACKS
"Thing-a-ma-jig". Actually, I don't know of any other servos but the two for the climate control. An old-timer may call them "dash pots".
climate control panel.
The body control module, on your 1997 Oldsmobile, is located on the rear suspension. The module is mounted on the passenger side of the rear axle.
Most likely loss of refrigerant.
Dual Zone Climate Control: -It is possible with dual zone climate control that every passenger in the car can have separate air conditioning temperature.
Try completely disconnecting the battery for 1 hour then reconnect it. That should reset some door that controls the airflow. I just experienced hot air blowing on the pass side and cold air on the drivers side. I did the reset and now I have heat on both sides. Hope it works for you.
It is for dule zone climate control
For the engine, under the plastic engine cover (sight shield). For the a/c, under the right side of the dash.