I am still trying to isolate the electrical issue on our H3.
To Reiterate.
The battery is draining dead over night.
The bell is ringing as if the key were still in the ignition.
Driver side door will not lock "as if the key were still in the ignition"

A senior member suggested in sounded like a worn key cylinder staying is accessory mode. However I would think something would still be on if in accessory mode.The ignition switch feels and sounds right, cranks just fine too and All the clicks feel smooth in the rotation and everything is off when its off.

I am not much of an electrical guy but I do have a small meter and it seems I have significant draw through Fuse # 05 (batt ign switch)

I pulled the fuse and touched both contacts and is drawing what I believe is 3.0 amps (maybe the wrong number because Im not sure of all the settings on the meter) Either way nothing else is drawing amperage!

I am going to leave that fuse out and see if it still drains the battery.

This leads me to the ignition switch as suggested. Should I replace the switch and cylinder? If I replace the cylinder then I will need to change the door lock too correct?

I have replaced older truck ignition switches and cylinder before but not one like this.
Thanks,

 

normal TOTAL drain is 110 ma/// 1/10 amp thryu one batt cable.

 

Yep you have a drain parasite.
Switch could be possible cause so to could other things.
Any aftermarket installs?
Chris

 

Everything is factory on this truck. (other than the battery terminals :-)
I re-charged the battery, pulled that #5 fuse, opened the door and the bell stopped ringing and the driver door will stay locked. I ordered a switch anyway! I left that fuse out and so far the battery is still at 12.37 volts. Guess I will see in the morning.

 

I put in the new ignition switch and completed the re-learn process, truck cranked and runs fine. On the surface it seemed fixed or Normal except now we have no door locks. The fuse is not blown! I'm not sure where to look now but I will keep digging and let you know what I find.

 

Pulled all the fuses and relays as suggested, touched the cables and waited 5 minutes, still no door locks or driver side power window.

 

12.37 is that what the battery was after you charged it ? seems a little low
if you can swap out another fully charged battery with the same cold cranking amps as the hummer see how that works out. it let ya know if it is the battery or not hopefully you have a truck battery hanging around to use take the volt meter to it hopefully 12.75 volts will be your reading. install and try

 

Yep doors an be a real b@tch. I've had this same crap with gf's h3.
Took removing the drivers side control unit and dismantling it cleaning it and reinstalling.
Chris

 

wow what a long day of "not my favorite kind of hummer work" installed the new ignition switch, removed, cleaned and lubricated the lock cylinder and all connectors, completed the relearn procedure, pulled all the relative fuses and relays, touched the battery cables together, waited ten and reconnected and then started it up. Ran fine and everything worked ,battery was at 12.97 volts to be exact, door locks and window worked and not dinging without the key in it. It was cold and late so I left all the trim off and hopefully tomorrow the battery will not be dead. Fingers crossed!

 

News?