reditr

Hi guys i have rebuild my motor and started the engine back. Well actually this is my problem when my car is at idle and the fans switch up the idle won t rise as it is suppose to do, as i switch up the car lights the idle would rise up as it suppose to do. when i am at idle and switch on the a/c instead of the engine idles up it decreases the idle. when i switch the a/c off then it would rise the idle as it suppose to do around 1100rpm and goes back to normal 800rpm. Can somebody help please ?