2000 770 a/c from hell

Hey guys, hoping someone can help me out here. Been chasing a/c problems since I bought this truck.

First thing I noticed the compressor was shot so went ahead and replaced it.

2nd thing was the APADS, it was not powering up. So I checked the a/c fuse and apad fuse first. Instead of apad fuse there was a wire which the previous owner wired to a switch/relay to control the engine fan manually.
Disconnect that, plug in the fuse,still no power.
Replace APAD with new one, it now powers up.

Tried to fill it up with some freon, the main line from the compressor had a leak at the valve stem. I tried to put a new stem in but the old one broke in there. Went ahead and changed that line along with all the orings in the system.

Give it another shot, leaking bad at evaporator.

Replace evaporator along with a new freeze switch.
It finally holds pressure.

I let the apad do a diagnostic and it checks out fine with a slow blinking green light.

As soon as I push the a/c button, the light flashes red 3 times, which means there a short or open circuit.

I tried to give 12v to the green wire at the apad connector, no go. I measured voltage at the compressor, this is where it gets interesting. It seems like there is always 10.8volts, which is also inverted. Going by the red and black wire on the compressor it seems to be inverted. Wether its inverted or not, i dont understand why theres always 10.8volts at the connector.
The apad does not through a red light until the a/c switch is switched on. When it does this, there is still only 10.8volts. The compressor never clicks. I gave it straight power and its working fine like that.
I checked the wires from the compressor to the apad, nothing is shorting there, connectors are clean no corrosion. Im starting to think something is wrong with the new apad I got?
I thought when you give power to the green wire, it bypasses everything and compressor should kick in, but when I do that, apad throughs a red light.
I also checked the power and ground going to the apad, got 13.7volts there. So good volts going in, only 10.8 coming out and it seems inverted to me as well. Im sorry for the long ### post, but now you guys know what ive tried so far.
Thanks in advance!

 

Well i just did another quick test. Guess I wasnt supposed to unplug the connector at the compressor whench checking for power and ground. I checked for power while the a/c switch is turned off and on, both times there was 13.7v. However no ground on the other wire. I gave it direct ground and popped a fuse, guess it didnt like that. So with this being said, the apad is functioning properly so far, not throughing a code at the moment, but at the same time compressor isnt kicking in either.
Could it be that the outside temperature is too cold for it to kick in?

 

Yes i tried giving it direct battery power and the compressor kicks in works fine.
I was reading up about the apad and it did say that if temps are too cold it wont turn the compressor on.
Im headed to miami now so I'll know for sure by tomorrow if it works or not

 

So I'm in Florida today and tried the a/c. It's throwing the same code, 3 red blinks.
Does anyone have a wiring diagram for this thing?
I tested the wiring from the switch to the thermostat and it looks good there.
I'd like to test from the thermostat to wherever the wire leads.
Any other ideas?

 

So I found a wiring diagram from apads website.
It walks you through on how to test all the pins at the connector to the apad.

Passed every test, proper power is getting there from the tstat. Only thing I'm not sure about was the engine fan output.
Its getting 5volts there, can anyone check on their truck at pin C and G with the ignition switched on, a/c switch on, and the connector needs to be unplugged from the apad.

I called the company who makes these modules asking if 5volts is normal or if its supposed to be 12volts. They said an engineer will call me back bur haven't heard back from them and I really wanna get this thing working, I'm boiling in florida.
Any help is greatly appreciated