use 2b&s size cable. any smaller is useless as it wont carry enough power. you can often buy pre terminated cables in this size from the local auto parts joint or auto-electrical shop. all connection points need to be clean to bare metal. a light smear of conductive grease helps with moisture proofing.

wire your batteries in parallel to get extra starting power. and use relays and starter soleniods to control the starter.

@trainzkid88 @neil Used 2/0 except for the 1/0 piece between bat + and the main power switch.

Overview/wrapup 

Continued discussion here with other questions/issues
www.acmoc.org/bb/discussion-d72/32503-new-d2-cont

Here's some pics of what I have - 1954 D2-5U #13247

Starter switch - turn left for glow plugs, right to start.  

Don't know why there is 2 solenoids - ain't broke so never tried to fix it

Claremontcat wrote:

Don't know why there is 2 solenoids - ain't broke so never tOneeried to fix it

One for starter, one for glpowplugs.

Daron

someone showed you the proper way wire a battery bank, you have the supply wires at opposite ends of the battery bank that way it acts like one big battery and you dont kill the one battery.