Engine does not stop when the air conditioner is on

My friends problem is this: I have a 2004 model 406 Automatic Gear 2.0 Gasoline (LPG) vehicle owner. Fan of Air Conditioner in the summer season 4. and after 5-6-7-8. I stop the car and remove the key when it is running at the ranks, but the engine continues to run. When I deactivate the air conditioner, even if I start the fan of the air conditioner at the 8th stage, the motor stops when I remove the key. It is not a problem when the weather is cold in winter. If there is any electrical leakage back from the air conditioner, there is no problem.

My teacher will first check the vehicle bsi (brain) - fuse boxes - electrical system chassis and contact will be checked.