On Tue, 23 Nov 2004 18:36:40 -0500, "SChevy"
wrote:

Recently I purchased a project boat and had to rewire from bow to stern.
The only problem I ran into was the nav/anc SPDT ON/OFF/ON switch has a
wire soldered between the two load pins on top. The wiring configuration
for the switch wasn't easy to figure out had to use a continuity tester.
The switch has five pins and the top center is the + feed, the bottom two
pins which are labeled red are actually for the light in the switch
itself. The problem is the lights come on together in either on position
NAV or ANC. Through research I think the switch is missing a DIODE that
can be used instead of the soldered wire that would block the current.
The prior owner must have run into the same problem. His solution was to
solder the wire on the terminal, thereby having all lights all the time.
I need to figure out how to determine the size or type of diode to use.
Any help would be appreciated, Scott

Short Story on Diodes.

Two main parameters of interest here.
1) Forward current max
2) Reverse voltage max.

You can measure the current desired through the diode.
Select a diode capable of handling twice that current.

The reverse voltage to specify is some multiple of the battery volts -
the bigger the better. The voltage spikes emanating from solenoids and
motors are considerable. Think 150V or 200+

Brian Whatcott Altus OK