If you fill out your profile, it will make it easier for others to help you when you ask questions. The Clutch pedal and A/C do not directly affect each other. What is likely going on...... Your car is likely a TT, the TT has a clutch booster that makes the pedal easier to depress. The clutch booster requires Vacuum to work. In order for the pedal to get harder with the A/C on, your engine vacuum has to be dropping when the A/C is on. This could happen if the engine ran poorly, and you increase the engine load by turning on the A/C. This could also happen if the clutch booster was weak and leaking, combined with the idle dropping with the A/C on. When you turn on the A/C, a valve at the driver rear of the plenum is suppose to raise the idle so the the idle is the same as when the A/C off or higher. My guess is your idle is dropping with A/C on because of a bad idle control valve or a poor running engine.
