Ok you guys are smart - explain to me why this happens.

If my car is sitting at an idle and I engage the electric window motor - the sound of my idle changes ever so slightly. Why? Obviously its something electric but what?

mine doesn't. haha

Mine doesnt either, do you have your a/c on when this happens? Maybe a grounding system would help.

No ac but I am running a Motec M800. Maybe it sucks alot of juice?

My Sentra used to do that, if you get a grounding kit it will stop

Hmm I always thought they were a bit of a joke - Ill look into it. Would this affect performance in anyway?

placing a load on the electrical sytem. Such a rapid and significant change that the car cannot adjust to it quickly or smoothly. It would be the same concept as having a high powered audio sytem( 1000W rms amplifier) thumping away. Your lights would dim and your idle would drop.

it just the alternator working harder to charge the batt (keeping the Voltage constant even thoe your drawing more curent) , more charging = more drag on the engine

you are draining extra juice from somewere elese the altenater cant handle it u need a detter altenater

Its a tiny change in the pitch of the idle - I think matt has hit the nail on the head.

My idle is set about 1000rpms - when the alternator works harder there is more drag on the engine and the idle drops to 998rpms (or whatever) resulting in the change in pitch.

Nothing wrong with the car. Thanks!

it can only make it better

no...

and if your car is on it's running off the alternator, so it's not charging the battery. it's just the fact that you're putting a load on the engine. that's all.

when you let your clutch out a lil in first gear your idle also changes. let it out too much and your car turns itself off.