Which batteries are which ?

Pass42 wrote:
kinda looks like the top are the chassis (engine start) bank, bottom house bank... disconnect one bank, try to start engine...if it doesn't start, you got the right one....if it does, you don't......

X2 This is the most simple and easiest way.

Ray

My battery set up looks identical to yours.On mine the lower batteries are the engine or chassis batteries. dave

Unhook the the red/black leads in the top picture and see what does not work... probably the engine. While you have the red one off, clean the other end.

kinda looks like the top are the chassis (engine start) bank, bottom house bank... disconnect one bank, try to start engine...if it doesn't start, you got the right one....if it does, you don't......

Hard to tell from those pics. Does either set have removable caps for adding water? House batteries are probably 6v batteries and would have 3 removable caps on each one.

Looking at the pic again it looks like both sets are wired in parallel, meaning both sets would be 12v batteries. Turn off one set and meter the other side of the large solenoid they're wired to, on the right side of the batteries.

I suspect the bottom set are the chassis batteries. There are 2 large cables off the positive post, one to the solenoid on the right and one probably to the engine starter. They don't run the starter power through the solenoid.