Posted by JimM on February 04, 2003 at 06:34:19:
In Reply to: Need Wiring Help posted by David Williams on February 03, 2003 at 19:03:11:
I've re-wired several small boats, and it's really pretty easy, if not tedious. We need a little more info on your engine, though. Does it have remote controls, with cables and wiring between the engine and helm station? Or is it steered by a handle on the engine, and the engine is completely self-contained? Makes a big difference!
In the former case, I'd expect the ignition switch to be on the controls, as it is on my Johnson 115. This makes things a lot easier. Cables coming out of the engine go directly to the battery and you don't have to worry about that.
You'll need a switched 12V line from the control box - that means it will have 12V available for accessories whenever the ignition switch is on. That line will provide power (not signal) to the tach. You'll need the engine's manual to find the right place to attach it (if older engine, see http://www.maxrules.com/fix.html for manuals).
Now you need to attach the tach to the proper connection inside the control box - again refeing to the manual.
Don't forget the "common" or ground line! Virtually everything gets attached to that.
Your lights get attached (through a fuse of course) directly to the battery, so you need battery terminals which allow for a smaller ring terminal to be attached. Voltmeter (not very common, but nice) goes to the switched line. The speedo is usually pitot-driven, no electricals except maybe a dash light. There are fancy (expensive) paddle-wheel speedos which would have to be wired.
A master switch is not too common on small boats, but not a bad idea. But DO NOT switch the heavy cables to the starter unless the switch is specifically designed for that very heavy-duty use.
The boats I've re-wired were previously wired by the factory (very simple, no room for accessories, and poor quality connectors), or by some previous owner who thought he knew how to wire a boat! I've seen some very scarey wiring!
Please do a quality job! Use heavy color-coded wire, go buy a couple of spools of 16 gauge and do it right. You should use black or green for ground, red for 12V feed and yellow for tach signal. Buy a little fuze panel that can go up under the dash. Make ALL connections with RING terminals. NO, DO NOT use spade or quick-release terminals! Use good quality crimping pliers, and SOLDER EVERY CRIMP. Use lots of tie-wraps to keep your wiring neat and out of harm's way. While you're working, keep thinking, "My mechanic is going to see my work, I don't want him thinking I'm a turkey!". Also, keep thinking what would be the consequences if a connection failed when I'm a LONG paddle from the pier.
There are books on boat-wiring, try Amazon. I'm not sure if they cover small boats or just cruisers.
Good luck, be careful, have fun! If you have more specific questions as you go along, don't hesitate to write.