Not charging at all?

This is going to be a little bit of a long question but I'm starting from the beginning about 2 weeks ago driving my truck and it had really weak battery terminal connectors so every now and then if I hit a pump one would pop up the truck would die I get out I put it back together and start up will it happen one night same exact thing I got out put the battery terminal back together nothing changed got someone over to jump me it barely take a jump and I got it around the corner where it was safe and I was in the middle of the road. The next morning, I went out it was a brand-new battery only had the battery week and a half so I figured it would recharge itself went out to start the truck nothing no power no nothing I'm not even a click, click, click, click. So, I called someone over to drop me again and it wouldn't take a jump. My thought was the alternator had gone out on me, so I went in a body a used alternator off Craigslist or something. Installed the new alternator I didn't charge my battery yet that was my mistake there tried to start it same symptoms try to start it again same symptoms tried to jump it same symptoms so I thought they sold me a alternator it was only $50.00 so I took both alternators mine and the new one to Napa where I had it a bench test done and they both passed although one had an issue with the pulley so I actually took that back to the wrecking yard I use my original one took the battery down to Napa and had it charged with their charger I also had them do an OBD reader on it and it was throwing no fault codes at all so somebody said maybe a parasitic draw the truck for about a day and a half and then same thing, shut off, couldn't get it started again. So, then I changed the voltage regulator for a brand new one still nothing and then I changed the air mass flow sensor, still nothing. Then I got a new battery too, nothing. Purchased a brand new alternator another brand new voltage regulator and a multimeter put it in just battery power I checked the cables or the plugs going into the back of the alternator and I'm only getting reading from the orange wire the white and the green there's no voltage reading at all none on or off position. I've checked all my fuses, they're good and now I don't know what to do I'm stepped when I bought another new battery says two new batteries. Can you please help?