ThreeBears

I am having some electrical issues and am rewiring some systems on my Fountain. The factory rigging is nothing to write home about and the previous owner was obviously clueless. But here is my question - I am working on my navigation and anchor lights ... they are fused at 5 amps, but all the wiring is #14 ... any reason I can't go back with #16 ... everything I can find says that 16 guage is good to 20 amps with is 4x what the circuit is fused for. What am I missing here?

Fenderjack

iTrader: (2)

16 should be fine, they prob use that as a fail safe. Like anything it is all under rated for safeness reasons.. Have at it with 16 but if 14 is there why not redo it in that..

John jr

boatcrzy

Not to highjack this thread but thought I would throw this out there. Who makes a good marine Knock sensor with gauge? Livorsi stoped making them, and cant find one on Gafrig site. I thought there was talk on OSO about someone who made one. Buddy almost burned down motor, bad load of fuel i think. Heard some builders use them and some rely on the merc ECU??? Any thoughts.



Thanks, dave

Audiofn

When dealing with DC you are dealing with a little different thing then AC. DC does not travel well over distance. So when you are calculating the wire required you need to figure out the draw AND the length. In the situation of a short run maybe the 16 is ok but then you have a very long run the 16 will show voltage drop. Not saying that 16 is not adaquate maybe it is maybe not. At any rate I use the fallowing calculator often to figure this stuff out. Use TINNED wire ONLY as once corrosion starts to set in you will get more resistance and voltage drop.

http://www.powerstream.com/Wire_Size.htm

Ted G

iTrader: (1)

Nice sight Jon, thanks.

Airpacker

FYI, Ford supplies some really nice tinned 14 or 16 gauge wire encased in a nice grey plastic sleve. It comes in 14 or 16 - 2 ( 2 conductor ) or 14 or 16 - 4 four wire. I use it on traile cords, under car wiring harnesses, boar wiring harnesses etc.

Motorcraft part numbers are 514-4, 514-2, 516-4 qne 516-2.
Good stuff.

ThreeBears

OK ... now for the really obvious question ... what is a acceptable voltage drop?

Audiofn

It depends on what you are running. For your regular bow lights probably 2 volts no problem. If you are running LED bow lights however you could probably have a 5-7 volt drop and still be fine. Don't forget that when your boat is underway you have 14 volts not 12 so a 2 volt drop puts you at 12 volts.