If you searched the same thing as me (dead battery) then it's pretty easy to see why you don't have an answer. Too many possibilities! Stuck relays, bad batteries, stuck seat switches...
Remember the recent thread by Kate with her stuck key and dead battery? This was there, posted by HummerTech:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">There are several reasons that a key may not come out of an h2. Here are the most popular 3 in order.
1. dead battery.
2. faulty ignition switch, usually accompanied
with ses light, trans not shifting properly
and maybe a few other weird symptoms.
3. a broken wire at the shifter assm. Every time the shifter is moved, it is moving some wires, and after they move back and forth a few thousand times, it can start to weaken those wires. </div></BLOCKQUOTE>
Labor Day -- A day for laboring on your Hummer.
