phyreminion

Whenever I run my heater, high or low, it makes my car idle low. It'll be fine at first, then drop to about 500 or less, kick back up to about 1100, then down. It does 3 times in a row, then idles fine for about a minute and a half. It's like clockwork. But if the heater is off completely then it idles fine. Anyone have an ideas?

NeoTokyo

A/C switch, if you get outside and watch your A/C compressor when someone turns on your heater or defrost you will see the clutch engage, thats because of a bad switch.

I gotta replace mine too.


Pretty sure thats probably your problem.