What is the problem, why the rpm goes down everytime aircon is turn on when it still idle?

Question

i have a car which is HONDA HATCH BACK MODEL, from stock engine 1300v i change it to d15b vtec sohc.. my problem is everytime aircon is turn on even idle the rpm goes down.. how many volt needed for the AICV to work?

Answer 1

There's nothing wrong.  That is quite normal.  The AC Compressor is engine driven and puts additional load on the engine while it is running.  That is also why running the AC reduces fuel economy.  Some of the engines power is used driving the AC compressor instead of going to the wheels.  

Answer 2

There is nothing wrong with your car. When you turn on the AC you are putting more of a load on the engine. It is common for the rpm to drop when you turn on your AC.