Originally Posted by wahvtec
1999 ranger 2.5 idles great until i turn that ac or heat switch on. As soon as it kicks on... idle drops and fluctuates around similar to maybe a small vacum leak or something of the sort. Is there a particular vacum line i should be looking for. Could the iacv be the culprit?
what you are feeling is the AC compressor kicking on and off. its more pronounced with the smaller motors. its nothing to worry about, its normal.