This was tough to follow so I'll do some guessing. Which battery group do you have your load connected to?
From what I read, the ARC will prevent discharging a charged battery into a discharged battery but you say your start batteries become discharged to the point where the van will not start.
Now again, I said I would be guessing so here goes..... there should be no reason for your start batteries to see anything outer than the vehicle's 12 load normally connected to the start system such as headlights, radio
and so forth.
YOur tv along with other powered amenities should be energized from the load bank. Does the load bank discharge along with the starting batteries?
Finally, how many watts does your tv require? I push the heck out of two 12vdc flooded batteries connected for 24 vdc (group 29??) when we are out. The tv, a 27" Sony is on most of the day until after 11pm along with a fluorescent light, the small lamp styles. We never kill the batteries. It takes about 1 1/2 hours to charge them in the morning with our generator
. Using the genny is fine because I need a lot of coffee in the mornings. It also heats the water
. Our solar as currently connected is mainly for our fridge. Next season I am connecting (at least I think I will connect) both house batteries to 24vdc and purchase
another 24vdc inverter
, install another 290 watts of solar and finally wire all my solar for 24vdc.