is the starter only wired to the primary battery then or should it also start if set to battery 2 only????

----------

That's a marine-type manual battery switch.  Might be Perko or one of several other makes -- no practical difference.  Works fine, until you switch it off with the engine running, which will probably toast your alternator and quite possibly ECU and other electronics -- do DON'T.  Perfectly ok and normal to run in BOTH while charging, but ordinarily should shift to one or the other the rest of the time.  If it has two extra small terminals on the back, that's for a field disconnect which will prevent the above -- you have to modify the alt and bring out the field line to the switch.

david

--
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"