I'm looking at the wiring diagram ... the alternator does trigger the AC/heater relay after passing through the starter relay. Interesting. The AC/heater relay supplies power to your 25 amp blower motor fuse and the 10 amp AC fuse. Hard to believe that all the alternators would have this same problem. Could be either relay. Rather than checking power to the switch and the blower motor, check power to the fuses. If none see if you are getting 12 volts from the white-green wire from your alternator. This is the wire that passes through the starter relay and triggers the AC/heater relay. The reason it passes thru the starter relay is to turn it off when you are cranking the vehicle.
You could also jumper 12 volts to that wire and see if you get power to the ac & blower fuses.