something is draining my batteries

You might check the battery kill switch.

 

Look at this vid:

He explains it very good.

 

Hopefully your four are individuals in a manner of speaking converging on a master power source for entire truck.

 

Over time i have used this method. After truck has set, over night or longer. Feel the batteries and see if one is warm to the touch. Never have used, but mayby one of the laser temperature tools may work better. If one is warmer than say ambient temp then that one may be the culprit. Another experiment is to disconnect them from each other for the weekend and see if problem is still there. Also to get a good reading on volts, i think they should be disconnected from each other for a long period of time so the good batteries are not feeding the bad. You may know this, but just saying what has worked for me.

 

having the same problem with my 2015 cant seem to find what it is and I have new batterys that passed load tests

 

After the motor has completely cooled down put your hand on the alternator and see if it’s warm.

 

on mine alt is cool cant find anything other than it will sit 10 hrs and drop to 9.5 volts

 

Maybe @pushbroom @spsauerland @Goodysnap have some ideas. With that much draw you should have a warm fuse or relay. Use the back of your finger or a temp gun to find it.

 

I have a 2016 Volvo. My symptoms were the same.

A Volvo tech looked in behind the metal/chrome battery turn off/on switch and showed me the plastic cover holding the wiring components, had cracked on the top, exposed the wiring and as such, was arching and not allowing the batteries to be fully recharged by the alternator.

Because these trucks are engineered with the capacity to shut everything down, saving enough voltage to turn the starter over, that's what was happening to me.