On the positive post of your engine/chassis battery will be 1 large cable to the starter, 1 medium size cable to the alternator, 1 medium size cable to the hydraulic jacks, 1 medium size cable to the battery control center (BCC) and 1 small wire to the EEC-IV engine/transmission computer for memory. Only 1 large negative cable, going to the frame.
BCC is the black box on firewall on drivers side. Wiring print for BCC is on the inside of the cover.
I have seen Bounders of your era with the positive post in the front and the back. Makes no difference which way the battery is turned, if the cables fit.
As for the house batteries, your coach came from the factory with 2 6 volt batteries hooked in series. Unless someone has added more wiring, the batteries have one positive going to the BCC and one negative going to the frame and the jumper between the batteries.
Richard