It won't do you any real good. The blower motor blows air through the heater core. If you have bypassed the heater core then its not hot= no warm air for defrost.
Uh.............he seems to be in Culver city?............. I'd say if you can stand the cold feet, the air blowing will probably be enough. I don't think it really frosts much down there, although I DO remember one time in San Diego.........
