Electrical Issue is Expanding

[Alberta Tahoe]

I had posted in a couple of threads regarding an intermittent short/open circuit on my 06 Tahoe.

http://www.tahoeyukonforum.com/threads/intense-electrical-issue.92892/page-2#post-1113447

http://www.tahoeyukonforum.com/threads/heres-a-weird-one.89340/page-5#post-1113443

Bumps in the road would cause a momentary disconnect of the dash instruments, the power door locks would open/close and in a worse case, the vehicle would drop into a reduced power mode.
An inspection of the usual suspects (battery connections, major ground points, etc) didn't show anything that I would think would cause this problem.
Now, I'll have to get into this on a whole other level as the condition has become worse.
The intermittent connection now appears to be permanent. After being away for two weeks and the truck parked, attempting to start it resulted in nothing. As if the battery was disconnected. Then the gauge function returned (with no fiddling on my part) although all indicators were at zero (as in the fuel gauge showed empty despite there being 3/4 of a tank). This is with the key in the run position. Attempting to start did nothing. Further to that, removing the key made no change whatsoever! The data centre was still active and the dash idiot lights remained on despite the key being pulled from the ignition switch.
To me , this points to the ignition switch as being the culprit but short of doing a re and re, I have no way to determine if that's the case.
Has anyone had a similar experience?
The chassis grounds are one thing and I understand how any one of them can cause a problem but a chassis ground isn't going to create this latest condition. This is more like a meltdown or failure of some component entirely.
It's far easier to ask here and go on other's experiences and repairs than it is to start taking things apart with no direction.
Thanks in advance.

 

[rockola1971]

It very well could be the ignition switch (not be confused with the ignition lock cylinder). I wouldnt mess with troubleshooting it to prove it. Ignition switches are cheap enough and not too bad to replace.

 

[afpj]

Here's a basic possibly stupid question ...how's your battery, not just your connection?

 

[Alberta Tahoe]

The only stupid questions are those that aren't asked.
The battery was fresh off the charger both before this latest go around again overnight before I started testing again yesterday. This isn't to say that there isn't an internal short (which would explain a lot) however the voltage is good. 13.08 volts to start and never dropped below 12.4 over the course of several hours with the ignition being cycled multiple times.
Of note: The dash instruments, indicating lights for the battery, low fuel (despite there being 3/4 of a tank), ABS and fasten seat belt as well as the information centre all remain active when the key is removed. That said, the information centre and low fuel lights are not at full brightness.
The ways I have found to turn off the dash is to do any one of the following:
1) disconnect the battery
2) remove the PCM1 fuse
3) remove the ignition relay
4) unplug the module (function unknown) on the firewall adjacent to the master cylinder
5) (and possibly disconnect the throttle body connector although I can't recall at this moment)
Any of the above will result in an audible "click" coming from the throttle body/IAC.
Back to the ignition switch. Is there a decent link to the removal and replacement? I've searched (and will again) however I really don't like the backyard self-made mechanic videos that consistently pop up. Information is lacking and procedure is thin or suspect at best.
Thanks for the replies. It's much appreciated.

EDIT: This video looks reasonable enough:

 

[Alberta Tahoe]

Well, it's not the ignition switch. The function between the old and the new replacement is exactly the same.
I think the body module (under the steering wheel) is next on the list.

 

[Alberta Tahoe]

In as much as I dislike swapping parts trying to find something that sticks, at this point it would appear my only option aside from towing it to a dealer.
As I understand it, any BCM I get will have to programmed by the dealer. Does that sound right? I'm hoping I can find something at one of the local auto recyclers.

 

[Alberta Tahoe]

(Copied from my other related threads)
http://www.tahoeyukonforum.com/threads/intense-electrical-issue.92892/

http://www.tahoeyukonforum.com/threads/body-control-module.93759/

Thinking this over and considering the real value of the vehicle to me (both in what it's worth and what it would cost to replace) I'm of the mind that buying a 2nd one that's still running may be the way to go. I've found a 2003 model and a 2001 for under $1500 either of which might be a suitable donor. At the very least I can say that they don't have the same issue mine does (in that they're driveable) and I'd have a pile of parts to swap in an attempt to isolate the problem. My thinking is that a dealer could possibly cost double that amount and still not remedy the situation.
This '06 was purchased for $5000 a little over two years ago and besides new shocks, front shock bushings and tires, it's required nothing other than oil changes and an air filter.
Still thinking...