Car Stereos/aftermarket radio and a/c
I just installed an aftermarket Kenwood radio in a 1996 Jeep Cherokee. The a/c was blowing cold when I dropped it off. Now it's dead. No fan, nothing. The heat works. Any ideas what he may have done? They say they will stand behind their work, but don't think it's related. Too coincidental to me.
In this vehicle the climate control unit is located right below the radio, and in pretty cramped quarters for a car audio installation. So I think there's a good chance that the problem originated with the head unit installation.
Looking at wiring diagrams for your vehicle, it appears that the power wire for the fan runs through the selector switch first, then from there to the fan speed switch. If the fan works with the heater, then you're not looking at a blown fuse, and it's not as simple as something left unplugged, or a wire pulled loose, at the back of the climate control unit. It really has to be a problem with the selector switch itself.
I don't know what the back of the climate control looks like, but it might be possible that a wire connection from the head unit has gotten lodged in the mechanism and is preventing the switch from making a contact. Another possibility is that something in the control unit was damaged when they were trying to fit the radio in place. And of course, it's not impossible that the problem is coincidental--it's a 20-year-old system, after all.
The first step is to remove and inspect the climate control panel. That's not very easy to do in this vehicle, because the steering column gets in the way of dash panel removal, but from the symptoms you described it's pretty certain that the problem is with the control unit.
Hope this helps!