Montana Motorcycle Charging Problems Custom wiring

Hi guys,

im running into a problem trying to run my Montana 700 on my rally bike. I purchased the motorcycle charger for it and it came with lots of wiring for all kinds of stuff like serial data and mic. I shortened the wires, removed the mic output and I’m only utilizing the positive and negative wires  

On paper it should work. I wired the positive cable up to my AmpLink which is sending 12v & 15amps to the charger but when I put the Montana on the charger it doesn’t register power. I used my voltmeter to verify there is power coming to the little charging pins on the charger.

At this point I’m not sure if its an issue with voltage or amps or what is going on, do you guys know of anything else to try?