[Daryles]

Classic symptoms of a 50A self resetting circuit breaker gone bad.

Take a multimeter. On shore power, ( in your case, truck 7 way cable) check each post of your 50A self resetting circuit breakers near your batteries. They should all read the same (about 12.4vdc).
Now remove shore power. Check them again.
Which ever one is NOT showing 12vdc on the post, it is bad. Replace it.

As mentioned above now is a good time to install an 80A self resetting circuit breaker and put the hydraulic system on its own circuit breaker per Lippert bulletin. You will find it in the files section of this website.