I was just wondering if anyone knew approximately what the max current you could pull through the fan header is. I want to add another fan to the tallismoon fan i already installed as well as do the shutdown timer mod, but don't want to overload it. i saw the OEM fan is 250mA and the tallismoon whisper fan is 160mA. Is it safe to run a single fan that draws more than 90mA along with the whisper fan, or should I keep the stand alone fan to 90 or below. Thanks ahead of time for the help.

The theoretical max current is around 2A, and it's not 5v it's 5v to 12v depending on the temperature of the 360, but that circuit seems to crap out long before that max rating is reached. The only thing you should have connected to the rear fan header is one set of fans (stock or Talismoon) and that's it, use another 5v source in the 360 for your other fans and such.

So even though the stock fan pulls 90mA more than the one i have installed, i should try and find a new location. What about the usb circuit? That is capable of 500mA if i'm correct. Shouldnt the fan circuit be close?

Yes use another spot to power your other fan/timer circuit, that rear fan header setup is just picky and seems to fry wherever it feels like when it's messed with. The rear fan header and USB circuits have nothing to do with each other and are completely different. The USB 5v is always on as well, even when the 360 is turned off.

So are there any switched 5v sources that would be safe to tie a fan into? Everything i have seen in any tutorials, even yours, only show continuous 5v stby power. I have a 5v fan that i would like to use for now.

Then you haven't been reading, because I have the 5v Switched spots in the pics I've done on the older version motherboard. If it doesn't say 5v Standby it's 5v Switched, from the third picture on all those 5v spots are Switched.

http://forums.xbox-scene.com/index.php?showtopic=613160

Well I did read, but the way you explained it was a little misleading, and no it never specified that they were switched, just didn't say they were standby. Thanks for the help, and no hard feelings.