View Full Version : Running lights

black lab
06-26-2012, 12:58 AM
I have a small boat that I'm putting running lights on. I was going to install a switch for the lights when I remembered that the switch I bought was a automotive switch that wouldn't be water proof. How would a simple set of alligator clips work. Someone at the parts store told me I should use a relay switch as well. ??? Jack

06-26-2012, 06:56 AM
Don't rig up anything half-baked on your boat. You will likely regret it later. You don't want electrical sparks on the boat (gasoline fumes), so the alligator clips is a bad idea. The automotive switch is probably OK if you can protect it from water an mount it in a box that seals the wiring side from water or corrosion. Wire is another issue. Regular wire in a marine environment corrodes from the inside as water wicks down into the insulation. Better to use tinned "marine wire" to avoid this.

black lab
06-26-2012, 05:52 PM
Right on with the "Sparks" being a hazard. I went back to the marina that I bought the lights from and got a sealed switch. I already had the Marine "tinned" wiring. The mechanic told me I didn't need a relay because it's low voltage. I'm not too sure about the amperage though. It's got me wondering now. Thanks, Jack

06-27-2012, 12:48 AM
If your just doing running lights, then a 10 amp fuse is more than adequate. No relay is needed . The wiring should be no smalller than 14 guage and the sealed switch is probably rated at 15 amps or more. You may want to add a waterproof boot cover to the switch if it did not come with one. I use dielectric grease on all connections to hold down corrosion.

black lab
06-30-2012, 12:27 AM
I"m using 14 gauge from the battery to the switch with a 10 amp fuse like you suggest, and 14 amp all the way though the system. Funny thing though, it looks like the lights themselves are only 18 guage, Good idea about the dielectric grease. Thanks, Jack

06-30-2012, 01:32 AM
Sounds about right.
Good luck.