H.O. alt and light are dimming

I order a high output alternator from www.mralternator.com a week or so ago, got it in tonight, I ordered the 200amp for a 94-01 ford truck (99 expedition with a 5.4l engine).  Got it in and it looked great, its a rewound motorcraft and the guys over there really seem to know what they are doing, the price was definetly right.  I put it in and fired it up, went out for a test drive, no lights dimming at all with bass hits (fosgate 1001bd for now, will be adding more amps soon), now this didnt surprise me as I never had the lights dim with my bass.  One thing that has always bothered me however, is that when I press the buttons to roll my windows up, my lights dim slightly.  This occurs even when the windows are up and I just push the button to see, I do this often to test it, its faint, but if you look at the instrument cluster you can definetly see it.  I was hoping that adding the H.O. alt would fix this, especially since I am going 70-90 amps over stock and only running one amp, Im a little dissapointed that it hasnt gone away.  Now it seems weird that my 1000watt rms amp wont make the lights dim when its cranked up but the simple press of a window switch can do it, seems like something is wrong there, I have only really noticed this in the last month or two, it could have always been there or it could have just shown up, I dont really know.

Also what method would you guys recommend for test the true output of the alternator, just hook it up to a multimeter and put it on amps?  Should I have all accessories turned up for maximum current draw and rev the engine to see if I can really get it to 200.  If I get a good 200 amp reading on my new alt then I would definetly recommend mralternator.com to anyone, the prices were reasonable, fast shipping, great customer service.

Thanks a lot,

Jeff

i belive it has nothing to do with your alternator. your lights and windows are on the same circut and when you have both on then it is pulling alot of power through one wire that powers both and it has to take some from the lights to use the windows. i believe that is how it is set up you would have to get a wireing diagram to make sure but im about 100% pos on that one.

Yes, the instrument cluster lights and the power windows would both be on the accessory circuit, so a slight dimming is not unusual, as sinister audio said.  As long as it's not your headlights that are dimming, if it is, then you need to wire some relays to power them directly off the battery.

DON'T TRY TO MEASURE 200 AMPS WITH YOUR MULTIMETER!  You'll fry it.  Even a good multimeter can only measure up to 10 or 20 amps.  It should say somewhere on the meter.  When you set a meter to measure current, you basically create a short from lead to lead (approaching 0 ohms) so that all the current of a particular circuit can pass through it.  I wouldn't even worry about how much it puts out as long as you don't have any problems.