With the picture above of the 4 wires coming un the battery compartiment....can Someone specify which is the 12 v (i know super short is 24v, and clarify the training 2 please
People tend to overthink this and it makes it confusing.
Think of what's happening, and perhaps it'll make things simple(r).
If your connections are still in place, you have 2 wires going into your Nato slave connector. This makes it dead simple as one wire is ground and the other is 24V. From there, you only have one other cable, and that's your 12V, which connects between the 2 batteries and it doesn't matter which one.
That's it -- you're done.
If you have 4 batteries, you simply double them up. Imagine stacking batteries one on top of the other and connecting each post vertically.
If you already took the batteries out, it's just a few more steps.
Nato recep is easy because it's just 2 cables and one is ground, and the other will go to 24V.
Figuring out the 3 connectors on the back, left side goes as follows:
1. Typically, the longest cable is ground. To verify, make sure everything in the truck is in the off position. That includes the master switch and lights. Use the multimeter on continuity or resistance setting and have one lead on the frame, and the other one on the battery terminal. Only ONE connector will give you zero (or very close, as in less than 1 Ohm) or resistance. If you have a continuity setting, only one cable will beep/buzz. That's your ground.
2. The 24V cable is typically the shortest one into the box. Using a multimeter check continuity on that cable to the starter. The starter will have 1 big wire coming from the battery. Again, you're looking for zero ohms or listening to the buzz. You might need to use a piece of wire or even a household extension cord to 'extend' your multimeter leads from one side of the truck to the other.
When doing this testing, it's always a good idea to test all the wires, to ensure that your results are ONLY TRUE on ONE terminal/wire and no others.
That ensures that a. you don't have any shorted/exposed wires, and b. that you didn't screw up and got a false positive reading.
Hit me up if you have any questions.