Originally Posted by Turbo_Bimmer

I've done exactly that to my 4.8is. I found the wire feeding the AE from the harness (reference in the DIY at the top of forum), and to keep the computer from giving an error in the dash, I installed a 200 ohms load resistor (one each side) between the AE feed wire and ground. If I remember, it was a power resistor (?10W) with a metal heat sinked body.

If you rewire the feed for your AE to turn ON with ignition at position 2, do like I did, feed 12V using a relay and a fuse direct from the 12V post under the hood. Some people here had problems using 12V directly from an already used circuit (without relay). To trigger the relay, I took the signal in the ECU box. At the ECU connector, there is one or two white and red wire(s). You can probe to be sure, but on my X, they were ON at position 2 and while the engine is running. When you turn the truck OFF, that signal will stay ON for a short period (10 seconds to 1 minutes) depending if the X still has things to do before completly turning OFF.
That's the same signal I used when I did my AE on my E46 and it worked well.
HTH.