Ok so 2001 Blazer lt 4wd

So I'd like to know where the source to this unusual problem lies.
When I try to start it by the key it either will or it won't

Starting procedure:

1). Get in rotate key to crank position (either start or don't)
2). If it don't crank, pop hood
3). Open relay box on fender
4). Remove starter relay cover and squeeze!
5). Close hood get in and drive

Any ideas where to start I figured the ignition is failing and needs replacing but not sure only DTC is Heated O2 sensor bank 1 sensor 1 (drivers side)

 

Do the lights still come on, even if it doesn't start? If they aren't, check your battery cables for corrosion. If they are, then it does sound like a new ignition switch is in your future. Or, try just replacing the relay first.

 

batt. is brand new less than 6 mos. old thought it was that at first. It had the black valucraft in it when i bought it, swapped up to a Duralast 75-DVL i believe

I'd like to note that i have the following
1). There is power to the starter
2.) There is power to and from 3 out of 4 pins on relay
3). The remaining unpowered pin i believe is from ignition which only grounds every now and again so u can start it from the ignition

The procedure above is how i start the truck which it does nicely.
The truck has plenty of power to all accessories and main circuits.

I also believe i have a bad MFS which is causing other issues described in another thread i wonder if these are connected

I will work on a video if i can to show u what i got going on

 

Here is the video i promised on what i meant above

Broken Blazer - YouTube
Video Link