I have a 2003 duramax,installed edge, awesome, great power and
+2mpg for the first 4 months. I was on a trip back east and when starting the truck in the morning (37deg out) has a very bad rough idle and was in limp mode,throttle not working right etc. First disconnected batteries to re-boot, no change.Unplugged edge and hooked up stock harness ran fine back to Arizona. Called Edge they sent me a new box, installed it worked great 1 day then at start up same thing. Plugged in stock ran great let truck warm up plugged edge back in no change-limp mode. Called Edge they sent entire new unit including the monitor. Hooked it all up, truck ran great on test drive then at start up the next morning limp mode again! Edge has been great helping but I really need to figure out what is going on???? I do not like driving with the stock setup. The only thing I have noticed about my truck is on startup it takes the alternator a couple of seconds to reach 14 volts, my gas truck reaches it almost instantly,is this normal? Could the edge be affected by low voltage? They say no but I was just wondering. Any ideas? Truck runs perfect without unit hooked up.

Your voltage stays below 14 volts for a couple of seconds because the glow plugs are still cycling. This is completely normal. Don't know what to tell you, mine runs fine with the edge, but my attitude monitor only lasted 3 days.

Also I think there is a heater in the intake that socks the batteries.

Correct, the air intake heater.