I was able to go thru O'Reilly's and get an AC Delco D1426D ignition switch and replaced it and actually did a video of that and have it up at you tube if anyone is interested. The very intermittent "stop" cranking problem, that only happens after is already cranking but has not started yet, is not fixed. later that day my girl was out and about and it did it again. So, now I have two apparently good ignition switches for this rig and the same switch fits up to 2009 TrailBlazers and other GM vehicles as well. The ones I have are the grey panel, updated contacts, designs. When this rig was bought in December of last year, it was stated as a well known weak spot for these TrailBlazers that the ignition switch contacts were crap. The old design was all black part housing. The updated ones are grey panel housing. I did not want to take a chance so I bought the only available ignition switch at RA that is a Standard Parts aftermarket part with the grey panel. I had never experienced the intermittent stop cranking problem but was trying to be pre-emptive. After the aftermarket part was installed, the intermittent stop cranking problem showed so I assumed it was the aftermarket part and eventually found the ACD part at O'Reilly's. The initial one I took out to replace with the SP switch was already grey panel but I had the new part in hand and went ahead and replaced. I installed the ACD part and still have the problem. I am convinced I have a voltage drop problem but I have not experienced the problem when I am in the vehicle and she only experiences the problem when away from home. I did inspect the cables at the battery and starter and all are completely clean and tight. I need to get it to stop cranking, hold the key in the crank position and check for voltage drop problems. I suspect a failing starter solenoid now but want to be sure. each and every time it has stopped cranking, if she cycles the key, it always starts, so far.