Hi robstyme and welcome to RV Forum. Will help you out if we can. Sure wish you had taken a picture and some good notes before disconnecting the old batteries - it would have made life much easier!
First, is this Bounder gas or diesel? And how many total batteries does it have?
In general, you will have tow sets of batteries in a motorhome - one set for the house 12v system and another to start the engine. They are not directly connected with each other. Instead, the engine is connected to a set of one (gas) or two (diesel) batteries and the house (lights, water pump, etc) connected to the remainder. There is a battery isolator that interconnects the two sets (called battery banks) for charging or emergency starting, but you don't have to worry about that.
RV 12v batteries are always connected + to + and - to -, but the house and engine batteries are always separate. You should find a red and a black cable pair for each.