electrical help need advice

[SkunkBoat]

its tough to explain it all without seeing what you have.
I use marine grade 16AWG for most things.

To calc current draw in AMPS in a DC circiut just divide Wattage of (incandescent) bulb by Voltage 12V
(a 12V battery is actually 13.8V but use 12 to err on the high side).


So a 10W bulb draws 10/12= .83 Amps

Add up the total watts drawn on any branch and divide by 12.
3 -10 watt bulbs draw 2.5 amps.

LEDs are a different story. Best to read your packaging for the Watts or current draw but a single (individual) led may draw only 20mA (.020Amps)
You can get a lot of LED light on a little power...

16 AWG wire can safely carry almost any circiut you are going to run on a V20. Even with multiple lights on a branch. Its cheaper than 12AWG!

save wire by extending a branch instead of running separate wires.
For instance. your red/green nav lights are on same switch. run wire to the green and then from there to the red.

You could go with 12-14awg on the pumps, VHF, and any Spotlight or 12V power outlet.


http://www.westmarine.com/webapp/wcs...ge=Marine-Wire