Thank you very much for the replies guys!!!
I ended up pulling the starter out myself. Took it to the shop and guess what, it worked just fine!
So I got back to my rig put it on, clamped the battery and it turned just fine.
I then drove the rig to the shop and had the battery and the alternator tested. Both were working fine.
So it wasn't the starter nor the alternator or the battery. The guy at the shop said that there was a high amperage drain (approx. 17.4) for no apparent reason.
He checked everything but did not come up with a solution. The drain would seize after a few minutes to 0.008 Amps. Long story short, I suspect the OEM alarm system.
It accidentally went off, while we were in the shop and the amp meter showed a 17.4.
Every time the alarm is annoyed it sounds the horn once as a warning before being fully triggered.
This I assume causes the on board computer to activate for a few minutes.
I recall reading in the manual that after 7 minutes all electronic devices left on will auto shut. I believe that every time the alarm triggers the warning the BCM stays active for 7 minutes.
At this time of the season the area I live in is densively populated so the warning signal gets activated a lot especially if a big truck, bus or a bike with low frequency exhaust drives by.
I know this for sure as I can hear the horn from my office.
This, combined with the fact that I hadn't moved the rig for 5 days caused the battery to drop.
The Juice was just enough to push the starter gear out but not enough to hold it in place so that the starter would crank.
I deactivated the alarm and parked my rig thinking that 5 days from now I will be able to prove my theory, (provided that I can stay out of my rig for thaaat long

) I'm already itching to get back in.. Will keep you posted!