HELP! About to purchase 1973 25' 'Land Yacht' but. . .

[rjbump]

. . .I opened the battery compartment at the rear entrance door side and see only a single wire that runs back to the inverter switch at the interior of the tralier. There is no battery (not a big deal, easily replaced) but what happens between battery and this 'cable' that exists? The cable is thin circa 1/4" diameter, black, and has a 'larger' and 'smaller' female connection point at the end.

What part(s) does one need to come off of the battery and connect properly into this cable? Are these readily available at an RV shop or custom order given the age?

Any insight would be GREATLY appreciated. Am admittedly an Airstream novice but anxious to join the ranks.

Kindly advise. THANK YOU.