Idle RPM drop when electrical accessories engaged
Recently I have been noticing an RPM drop whenever I open a circuit on an electrical component. For instance, whenever my power windows engage, I feel a significant RPM drop. When I press the brake pedal just enough to engage the tail lights, I get an RPM drop.
Randomly, when I am idling at a light or idling in a stationary position I get an RPM drop, I presume sometimes when the electric fan comes on, other times I am unsure. The RPM drop is from the standard 750 to about 500 rpm and the car really vibrates, just like a stall is about to happen.
I am curious as to whether this is an alternator/alternator voltage regulator issue or a TPS or IAC issue. I wanted to get other opinions on the matter, so I am looking forward to responses.