What is accepted battery draw down?

A relay in the same chassis box clicked a few times then every thing cam back to life. What does the same chaissis box do?

 

Ok I started this thread the other day. Not realizing I was goneing to remember to buy the batterys for the voltage meter, but then walk off and leave it at the house. I had recently as 2 weeks ago cleaned and righted all the termnals.
Only one was loose.
I will be back at the house to pick this up this chore this weekend.

What we are working on is a 2016 DD13 automatic. Current systems include.
When I put the flashers on, all in cab electronics flash for a micro second unless the bunk lights are on. Then the bunk lights flash in rhythm with the 4 ways.
When the bunk lights are not on, I loose every bit of power but not the engine. And then the 4 ways stop flashing,
When I put the cool air fan on it blows decent up to number 5, after 5 or when the a.c. is on any level I loose all electroics as mentioned above.
Three when I have either the flashers or the a.c. on. Then add the other it kills the engine. Sometimes like a power and distribution box. And some times it will take 10 mins for the self resetting relay to cool off enough to restart.
I 've only done the complete kill while testing to see what would happen.
Three weeks ago it was charging at 14.0 to 14.3. Now it's .0 to .1. I added nothing new to it. I did change the tension pull assembly. But had this problem prior to it.
Today I pulled the switches and seen no broken wires.

 

The meter died before I could. I will this weekend when I get back in.

 

Whats the proper way, do I put the red lead on the power in cable and the black lead on the alternator it's self?

 

I just check the batteries.the truck has been off for 30 ish hours. They are all showing 13.08.