2005 Silverado- Cluster, brake, and blower issue

[tnrambler]

2005 Silverado 1500, base fleet with the 5.3-

 

I was driving down I-65, and all of a sudden, sensor gauges all went out, gear selector, etc- but speedo, tach, and odometer still worked.

Same time, air conditioning went out- still blows air, but no A/C. The gauges would occasionally reset to normal, but would shortly after die.

Saw the security light flash as well as the brake indicator light. As I was hauling furniture, and had the dog with me, I was hesitant to stop, as the truck was driving just fine, and feared it would not restart due to a security feature. Fortunately (maybe?) this is not the case- truck cranks just fine, but gauges don't function at all at this point.

 

I had had the cluster rebuilt in april due to faulty speedo step motor, so first thing, tried to clean out the plugs and contacts off of that to ensure that was not the issue.

Ran into an interesting issue when I was replacing the cleaned cluster back in the dash-
Now, when the truck is off, key out, and blower switch on: if I hit the brakes, or turn on the hazards, the blower turns on.

It even cycles with the lights on hazard (on when lights are flashed, disengages when lights are off.

When the key is in, and the hazards or right turn signal are on, the indicator lights stay lit. Turn the key off, they function as normal.

Air bag in picture is normal- vehicle was in previous collision, and the previous owner replaced the air bag on driver side with a plain cover.

As this electrical line literally spans the length of the truck, and I have already checked fuses and breakers and the connector for the cluster, any one got any ideas where the likely point of failure(s) is?

I am thinking ignition switch is likely culprit, but unsure how to diagnose.