My car shake when air is on.What i need to do

on 1998 Volkswagen Beetle

when turning on air car seem to want to cut off

Asked by for the 1998 Volkswagen Beetle
Make sure the compressor is secure, after that I would guess the air conditioning load on the engine is causing a misfire or the idle air control motor is not properly adjusting the idle speed. It's hard to guess without being able to experience the problem and do some basic diagnostic tests.
Do you think the coil would be another factor