RPM Increases When Defroster Is On

[kimcheefists]

Well like the title states, when idling, my RPM increases whenever the defroster is on. When the blower selector is in defroster or defroster/feet, engine speed increases to 2K. Any suggestions as what could be causing this?

Something that I think may be causing this is that the A/C belt isn't attached but I wanted to see if there could be anything else wrong.

 

[->PrOjEcTGS<-]

This is because the ECU is programmed to know that when the A/C or defroster is on it needs to raise the RPM to compensate for the load that the engine is now under.

Without the A/C or Defroster mode on what does your car idle at?

 

[kimcheefists]

Without the A/C or defroster on, it idles at around 750 after it's warmed up.

 

[corsair231]

If the computer thinks the A/C is on for the defrost cycle then it tries to raise the idle by adding fuel and air. Without the belt on, the engine doesn't see the load so the increase that is supposed to be only a few hundred rpm actually ends up being several hundred rpm. If anything is out of adjustment (idle wise) I could see it ending up being 2k.

 

[kimcheefists]

I don't think anything is wrong with my idle. Like I said, it idles at 750 when the A/C or defroster is off. It only revs to 2K when the A/C or defroster is on. I guess I'll just come back to this thread when I replace the A/C belt...