[Lost in the 60's]

I have a 2011 1500 with a Boss plow on it. I know this has some sensor for when the battery is fully charged, the alt will cut way down on charging, but this happens when I use the plow now. If I don't shut the engine off and restart it, the alt never comes back on line and I drain the battery down with the plow.
Anyone come across this and has a fix ??
Truck as 125k on it and original alt.
Thanks