Help: Car wants to die when AC turns on

[Gabe92RTTT]

Hi all,

Normally my car idles at 800 RPMs but when I turn the AC on it drops to 500 RPMS. Once the car has been driven awhile the RPMS will pick up to 1500 RPMS and when I switch off the AC, they shoot up to 2000RPMS!! All the tune up stuff has been done and the timing and BISS are ok. What can this be? I just replaced my alternator/battery and they didn't solve the issue.

Thanks for the help.

 

[temfate]

Your idle speed controller or ISC is bad... Check out www.vfaq.com under DSM... You can find everything about how to diagnose and fix every problem like this! Here's a direct link:

http://dmtalon.v8eaters.com/ISC.html

 

[Gabe92RTTT]

Hey thanks a lot! I will go home and test the resistance tonight

 

[Colossus]

Yes, that's for sure it. Eventually upon putting the clutch in you're car will stall out, or stall from a high RPM "clutch-in" drop. Mine was bad and had this problem. Even after I replaced it, my car shakes like hell and rpms drop a tad whenever I turn it on at idle.

 

[rjdavis21]

mine runs like crap with the A/C on thats why i never use it unless im on the interstate...but it only acts up sometimes with no A/C how much are these ISCs new...they are like 90 bucks on ebay used....