Idle drop with accessory load

[RS12Turbo]

What makes the idle raise when an accessory is turned on, like the headlights? Right now my idle drops when an accessory is turned on.....Is there something with the wiring I need to wire in somehow......or should the ecu already be sensing this?

[float_6969]

The AAC valve is responsible for maintaining idle.

[dattodude]

The drop in idle is caused by the current drain making the alternator harder to turn. This is why the engine slows down.

Either get a bigger battery, service/replace your alternator, clean your headlight connectors and relays, or get smaller wattage globe inserts.

You are correct in thinking that this is the job of the AAC. However if the AAC is already operating at full PWM cycle because it's air gallerys are blocked, then it cannot let any more air past the throttle body to compensate.

Cheers.

[float_6969]

I've had 2 CA's with this valve not functioning. I assumed it was a typical problem.

[RS12Turbo]

Hmmmm, I'll check the aac and see if it is functioning correctly. I have a red top optima and it reads over 14 volts at idle, so I doubt it's that or the alt.Didn't have this prob with my ca-et, the idle raised when something was turned on....so my guess the aac is not functioning.....or because the motor swap is in a s12, maybe the aac isn't even hooked up.........