Low idle RPM problem

[SpoolinGSX]

The problem is that when i have accesories on like AC, i cant idle because the RPMs drop to around 300. When i turn off the AC it goes back to normal around 800. I thought there was a sensor that was supposed to adjust for the AC and bring the RPMs back up and was wondering if that could be broken and where it was. At night when i turn on my headlights my RPMs drop as well and dont come back up, not sure if this is supposed to happen or if maybe due to the same sensor problem. Any input would be good cause i have no experience with this kind of problem. Thanks.

 

[Megaman]

could be a dying alternator

 

[Thunderskull]

Originally posted by SpoolinGSX
The problem is that when i have accesories on like AC, i cant idle because the RPMs drop to around 300. When i turn off the AC it goes back to normal around 800. I thought there was a sensor that was supposed to adjust for the AC and bring the RPMs back up and was wondering if that could be broken and where it was. At night when i turn on my headlights my RPMs drop as well and dont come back up, not sure if this is supposed to happen or if maybe due to the same sensor problem. Any input would be good cause i have no experience with this kind of problem. Thanks.

This can be one of 2 things. First, it could be your alternator. Test it with a multimeter. It should be putting out between 13-14 volts. Now, it could also be your idle speed control motor. Are you having any other problems related to your idle? Do you have any idle surge or does your car stall somtimes when coming to a stop?

 

[SpoolinGSX]

I dont have any idle surge or stalling at idle. I will check the voltage on my alternator and hopefully that could give me some insight. Thanks for the help.

 

[Defiant]

Is your ISC coming on like it's supposed to when the AC is on?