RE: [omc-boats] wiring help

Hi David,

I now realize that I forgot to answer one of your primary questions
regarding how to treat or coat connectors.

OMC originally used a black rubber coating material. You'll find it
applied to the starter relay and tilt relay connections. Forty years
later it's brittle, nasty stuff. I'm guessing it's probably similar to
the "liquid tape" like products you can buy at Home Depot or the marine
stores. It did serve to seal out corrosion and to also insure against
physical vibration where the threaded electrical fastener can loosen
over time. Personally, I'd rather use Permatex RTV instead of the liquid
tape, as it remains more flexible over extended time. And then depend on
a sealed terminal or combination of heat shrink tubing to help seal the
wire/connector from corrosion. Another benefit of heat-shrink tubing is
it acts to physically strain-relief the wire/terminator physical
connection from damage/disconnection.

Ethan's correct in that a good di-electric (grease) can also help seal a
connector, but offers little vibration resistance. The point is this:
not just one chemical product does it all. Don't be afraid to try out
several.

Also, I'm not clear which starter connection(s) you refer to. The very
large battery cables are easily replaced but don't typically come with
adhesive-sealed heat shrink lugs. Also, traditional "flooded" lead-acid
batteries contribute gas venting which leads to accelerated corrosion
and frequent maintenance (the ole baking soda cleanings to neutralize
pH). Consider using an AGM or spiral-technology battery like Optima, to
greatly battery and battery cable maintenance.

Also take care to document the tilt relay wiring. They are easily
confused. (I know I've done it!)

Ethan's also right about wiring colors. Very few people who undertake
wiring projects rarely bother to document their work. (I'm guilty, for
sure.) Not only will the next owner not have a clue, but I'd guess most
of us will forget six weeks down the road how we re-did something. E/J/O
did a great job following standards and documenting their products, we
should all follow the excellent example the E/J/O engineers set for us.
It only takes a few extra minutes to write it down, then stuff it in the
toolbox or shop manual.

Lee Shuster
Lib1@...
 
 
-----Original Message-----
From: owner-omc-boats@... [mailto:owner-omc-boats@...]
On Behalf Of Ethan Brodsky
Sent: Wednesday, May 03, 2006 1:39 PM
To: omc-boats@...
Subject: Re: [omc-boats] wiring help

On Wed, 3 May 2006, Ryan wrote:
> Thanks Lee. I was just at West Marine today! I found the Marine
Grade wire
> that is tinned and rated 120 degrees C. for engine compartments. They
have
> your basic colors but I just bought white and black. I saw the heat
shrink
> butt connectors but they were like $22 for a 10 pack and I'm not sure
what I
> want to do yet. They also have a wide selection of stainless steal
bolts
> as well as brass. I think I will be able to find everything I need at
that
> store. One question I still have. On the starter, if I use the
tinned
> connectors, is that good enough or should they be also coated with
grease,
> paint, or RTV? Or should I try to make some sort of boot to seal it
up?

If you're going to rewire the entire engine bay, I'd suggest getting
more
colors than just white and black. I've trouble-shooted systems where
someone wired everything in one color - I'd never do it again. At least
get the standard colors - red/black/yellow/green/blue/orange - in,
perhaps
16 AWG, and then red and black in a larger size. I think there's a
standard color scheme that's recommended for boats.

I'd probably put a bit of electrical contact grease on the terminal to
prevent corrosion. The Stabilant-22 Lee mentioned looks like an
excellent choice. I've never done saltwater stuff - most of my
experience
is in automotive applications - so I've always just used cheap grease
from a car parts store.

Another resource you'll want to refer to is the US Coast Guard's
"Boat-Builder's Handbook", which lists all the regulations relating
to boat design and construction. There's an electrical section
that will help you a lot.

  http://www.uscgboating.org/safety/boatbuilder/index.htm

Ethan Brodsky

-- 
<A HREF="http://www.engr.wisc.edu/~brodskye/"> Ethan Brodsky </A>
UW FutureCar Team Paradigm: Two-Year FutureCar Challenge Winner
UW-Madison Clean Snowmobile Team: Winner of the 2004 SAE CSC
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