I just had my Electrical Ignition Switch changed in my 1990 Honda Civic. When I got it back from the mechanic, the blower for my heater/ac didn't work. Would that have anything to do with the work they did changing the ignition?

It may have. Check the 30A Blower Motor Fuse in the under hood fuse box. If the problem persists, check the connector going to the blower motor.