Kevin,
Thank you for your answers to so many electrical questions. I plan to redo my fishing boat wiring and have a couple of questions.
My 1977 18 foot Starcraft has an outboard motor with it’s own circuit and will not be involved in the rewire.
My current marine electrical has a battery in the back of the boat, approximately 16 feet from the fused, marine electrical switch panel.
The old boat wiring is a rat’s nest with each circuit wired individually.
I will be using the standard small boat items: a depth finder, FM radio, bilge pump, navigation lights (bow and stern), gauges and a rear-mounted gas tank.
I would like to run a duplex cable from the rear battery to the switch panel. The total duplex run would be 32 feet and the total amp draw should be no more than 30.
I think I need a 10 AWG duplex cable for the 30 foot run and 16 AWG boat wiring for leads from the switches to the instruments (+) and bus bars (-)?
Does this sound right?
Thank you for any help you can provide.
Teddy
Hi Tom,
I would recommend using my boat wiring size calculator to answer your wire size questions.
- Leave the voltage drop percentages in column B and G alone.
- Enter the current draw of you switch panel devices in column C and H.
- Enter you total wire length run in inches for each device (switch to device and back to ground) in column D and I
- Enter your total wire length run in inches for the panel feed (battery to panel and back to battery) in cell 25D – 384 is your guess.
- Your wire sizes will be in Column E and J.
Let me know if you have any questions,
Kevin




