Weak battery or bad alternator from factory?
 

I've noticed my FR-S does an RPM dip whenever it's running and I use electronics. Power windows, dip. A/C, dip. Signals, dip. It seems like the alternator is simply too weak for this car.

Does anyone have similar experience? I was rolling into the carwash last night and when I rolled the windows up the rpm dipped (annoying). So I just clicked the switch up again and the RPM's fluctuated. Just the activation of the switch alone caused a light dip.

Pretty terrible if you ask me.

Just for A/C everything else is fine

I've noticed this myself. The first time I felt the slight idle dip I immediately thought of the alternator. In traffic, I get a slight idle dip when my headlights automatically turn on. :iono: