But remember that you lose about one half volt thru the diode. For
incandescent light bulbs, the change from 12 volts to 11.5 is significant.
Better have bulbs with more than the required range/brightness.

Roger

http://home.insightbb.com/~derbyrm

"ray lunder" wrote in message
...
Va-voom! thanks.

On Tue, 22 Aug 2006 13:26:42 -0400, "Glenn Ashmore"
wrote:

You need two diodes and a Double throw double pole (DPDT) switch with
center
off. The switch will have 6 poles. A pair at each end and a pair in the
middle. Connect the middle pair to your DC power and ground. Connect the
end poles diagonally across from each other and run from either end pair
to
the lights. I use that method to control the direction of my fuel and
water
transfer pumps.

At each of the two lights add a diode in series with the direction
opposite
each other as Heikki described.

With 3 wires and a double gang rotary switch you can control 6 lights.