your drain line for your ac evaporator core is plugged up. A service station can blow this out for you.
With torches and soldering sticks.
You have to determine the source of the leak then decide on how to fix it.
Are you sure you have a leak? Most of the time when using the air conditioner, your car will appear to be leaking water or dripping underneath the vehicle, towards the front.
can you block the high side on the ac on a car to stop a leak
You have to replace it. They are designed to leak when they are going bad.
Look for a vacuum leak.
Find and fix exhaust leak
Get a new car
This normally indicates a refrigerant leak. STOP USING YOUR AC IMMEDIATELY AFTER THE ACKNOWLEDGEMENT OF THIS SMELL!! The fumes from the fluid in your AC system are highly toxic. The leak needs to be sorted out before the AC can be used again.
Depends on where the leak is located, and how much labor will go into fixing it.