200 Elantra AC blower problem
 

Air condtioner works fine except when I accelerate rapidly. If I "stomp" on it to enter the freeway, etc, the blower goes wonky for abt 15 seconds. The cool air stops coming out of the dash vents and starts coming thru the defroster. 10-15 seconds it resumes coming thru the dash vents.

What on earth causes that?

correction * it is a 2000 Elantra*