Re: [omc-boats] Re: boat stuck

On Thu, 8 Dec 2005, mark wrote:
> if the electorshift wires are disconnected-does it fall out of
> gear-nevermind i remember reading it defaults to forward gear under
> fail so you can still get 'home'
> -if i allpy juice to those wires will it kick it out of gear? hotwire
> it. is the unit the ground? or is there dedicated ground wire?
> thanks for teh excellent advice and troubleshooting.

I believe it will fail into neutral, not forward. The coils require
continuous 12V power to stay in gear. You can check if the coils are good
by putting an ohmmeter between the green wire and ground and the blue wire
and ground. One is forward and the other is reverse, but I don't remember
for sure which is which. I seem to recall that green is forward ("green
means go" and blue is reverse "blue means backup"), but no guarantees
there.

The coils are grounded through the outdrive case - make sure you measure
off a clean point like a screw head and not a painted or corroded aluminum
surface.

I believe the resistance should be in the 2-5 ohm range, but I can
double-check tonight in the manuals. "2.3-2.6 ohm" rings a bell for some
reason, but I don't remember for sure.

If the coils are bad I'm guessing you'll see an open circuit. If the wire
is bad you may see either an open circuit or a short. Also check
resistance between the two - it should read twice that of the individual
ones. If it does not they may be shorted together.

The shift wires can be disconnected in the engine bay - there's some
spade-like clips in there that go between the boat wiring harness and the
outdrive wiring harness. The connections are probably be covered by small
boots made of gummy rubber. Look for some blue and green wires go to a
cable that passes through the top port side of the intermediate housing.

The forward/reverse coil power is wired directly to the push-buttons in the
remote control (throttle handle unit) - there are no relays in the circuit.
While you have the engine-bay connection apart, check that you're getting
power there. Turn the key to run, pull the throttle back to idle, push the
forward button, and see if one of the wires is hot. Then try reverse and
the other.

One more important thing to check is ground continuity. Check resistance
between the outdrive and engine block or negative battery terminal. It
should be very low (0.1 ohms or so). There's a stainless steel wire that
goes from the outdrive to the intermediate housing. I can't remember where
it connects on the outdrive, but if everything else checks out I'd take
each end off, scrape underneath them a bit, then reinstall with conductive
grease.

The manuals I have caution about applying power to the shift coils out of
the water. They say the coils are cooled by water and will overheat if you
leave them energized for long periods while dry. Just based on the amount
of metal between them and the water, I've been assuming it's ok to keep
them energized for several minutes.

One more caution is that it is supposedly very easy to damage the shift
springs when shifting into gear at higher RPM. A mechanic told me I should
keep the idle as low as possible - 600-700 rpm is ideal - since shifting at
higher RPM (even 900-1100, a typical "fast idle") can break the springs.

Ethan
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<A HREF="http://www.pobox.com/~ebrodsky/"> 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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