{sigh} Ive explained already a half dozen times. If you dont want to listen, have it your way. The obviousness of the issue should be apparent to you, as you say it does the same thing with a new alternator.
of course.
no problem to fix.

 

Every one stop and count to ten and take deep breaths.

Mitsiboy - Sounds to me like it is just this intial startup load dropping your voltage for a fraction of a second. Does not seem like anything out of the ordinary to me. Ever see a hair dryer make the lights dim for a brief moment in a bathroom when first turned on? It is the same principal. If your steady state voltage under load is fine (which you report it is) then I really don't think you have a problem. Could Mitsubishi have designed the electrical system to buffer these high spike demands better? It is possible. This is exactly why the stereos with big amps and huge speakers need big capacitors in the system. They provide contiuous voltage levels during spike demands where the normal car charging system can't keep up.

 

Okay, having now heard your issue is only temporary when the load changes, I take back my original statement - dude your electrical system is fine and is performing exactly the way it should be.

What a bizarre thread this has turned into.

 

Do any of your cars lights dim, fan motor slow down, when the AC comes on. Imean while you are driving not sitting still. It looks like my lights dim for a 1/2 a second. This is the problem. I have never had a car that has had this problem. I am pretty sure if your cars lights dimmed every 45 seconds your car would be in the shop also.

 

The only time I've ever experienced this in my car was when my battery power was low and that was because the battery had issues charging up. Aside from that, no. My wife's 2005 Grand Caravan doesn't blink with the front and rear A/C set on 65 deg, radio blaring, pressing the brakes, or even at idle and all this at night. I will admit that it has done it before, but nothing to concern myself with since it's a once in a blue moon thing. So, yes, once in awhile a slight dimming is normal, but not every 45 seconds.
Yup, if my car blinked every 45 seconds, I would definitely not let it go.
Things I would check in this order...
Belts, pulleys, fusible links, tensioners, battery, connections to affected items. Everything else should be covered under warranty otherwise I'd say to check them. Press the issue, it's not normal for it to happen every cycle and it's not going to go away on it's own.
It may not be an electrical load issue, it can be a mechanical issue, regardless of what it is and when it's doing it, it's not normal, not on a new vehicle....not to dim every cycle.
Maybe it's an electrical gremlin, maybe it's a mechanical gremlin, maybe there's another variable that isn't being told, I don't know, but in order for any tech to give you a proper diagnosis and fix, they have to duplicate the issue.

Anyhow, good luck....y'all are doing a good job keeping it civil. Remember, we're all doing the same thing trying to reach the same goal

 

Okay I am changing my mind back to the original - there is a problem. Pardon my temporary lapse of sanity!

 

AARRGG!!

NORMAL! NORMAL! NORMAL!
how many times does it need to be said?

 

then mine must be abnormal, and I have to take it in to be checked. Mineit does NOT do this. I tried it in the dark garage. Turned on every electrical thing i could find, turned on the lights against the wall and flipped on the AC. The lights never waivered in the slightest when the compressor turned on or off. Mine is a 2007 LS 4WD with 450kms.