Possibly the switch faulty and works in one position only. With the switch
out, check that the switch positions work (verify the contacts) before
fitting everything. Saves you the hassle of ripping it out again if it is
faulty.

Tan PS

"Henry" wrote in message news:51BVb.441665$X%5.5576@pd7tw2no...
I recently bought an O'day 27 and have come across a surprise in the
wiring
of the battery switch.

This is the usual 1,2, both or off.

The two batteries are wired with their positives strapped together, and
the
negatives disappear separately into the switch.
All positives are taken from the deep cycle battery, including the
starter.


Tomorrow I intend to remove the switch with a view to rewiring in a more
conventional way.

Can anyone speculate on why the wiring should be as it is. Also, is there
anything I should know to prevent blowing the alternator?

Thanks in anticipation

Henry