[C38] Two Electrical Problems

[Julian Adams]

Thanks Les, that's very helpful.


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Julian Adams
Department of Molecular, Cellular and Developmental Biology
University of Michigan
 830 N. University, Ann Arbor MI 48109-1048
Tel. (734)-763-3431; Fax (734)-647-0884; Cell (734)-239-3627
E-mail julian at umich.edu
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-----Original Message-----
From: Les Howell [mailto:hlhowell at pacbell.net]
Sent: Friday, June 27, 2014 2:47 AM
To: listserve at catalina38.org
Subject: Re: [C38] Two Electrical Problems

Hi, Julian,
	The GPS issue could be a number of things.  If you have the old fuse panel
still in place, the fuse and holder could be corroded.  The C38 are not
spring chickens any more, and things get moldy...
	Also when Nancy and I got JACE (formerly Infinity, and now Knee Deep or
???) There were a number of the three way rivited terminal splices in the
wires.  These things are like 3 eye terminals riveted together.
Every one of them was corroded and intermittant or high resistance.  I took
them all out.  My trick was a barrel connector with the input side being a
single wire doubled back on itself, twisted and then crimped, to the two
wires  in a bit of heat shrink longer than the barrel connector, twisted and
crimped on the other side, and the whole shebang covered with that bit of
heatshrink and shrunk.  At least where I could put the heatshrink on (some
were located where I couldn't apply the heatshrink or heat it properly.)
Another place was the fuse panel fuse sockets were really corroded.  I used
some 300 grit wet/dry sand paper and burnished the fuses and the socket bits
to get a better connection prior to my replacing the whole panel with
circuit breakers.

	Also, prior owner/catalina/various shops had used several balls worth of
electrical tape splicing bits of wire together for many of the electrical
connections.  I did my best to find and eliminate them.  Good luck on that
one.

The alternator controller is a way to boost the charge current.  It is
pretty abusive in some cases, but you can use it to set the charge current.
When the motor is running, check the voltage at the battery.
If everything is good and the battery is full, it will be between 13.6 and
14.2 volts.  This voltage is due to the internal drop of the battery and the
current coursing through the wires.  The regulator monitors the current and
the voltage.  To get faster charging, some one thought up a way to change
the comparator to the voltage regulator to make it run a bit hotter, and
also to step up the current supply by causing the field to get more
excitation in the alternator.  This little trick has some tradeoffs though.
	Pros:
	1.  can charge the battery faster and/or at a lower rpm
	2.  gives you more current available when running the engine to both charge
the batteries and run the house.

	Cons:
	1.  hard on the battery and alternator.  Most of the commercial units will
have some kind of limit on how far you can push the alternator, but this
only works for a specific alternator, as the current limits and cooling of
alternators vary quite a bit.
	2.  has to be monitored to prevent boiling the batteries.  If a battery is
charged with too high a current it out gasses and the plates break down.  A
limited version of this is sometimes called equalizing a battery, but that
is very tightly controlled and time limited.  When a battery is abused this
way, its life will be shorter, and if too badly abused can produce an
explosive situation due to the output of both hydrogen and oxygen in what is
called out-gassing.
	3.  Alternator may catch fire if the current is pushed too high while the
alternator is turning slowly because the only cooling is provided by the fan
that is part of the spindle where the pully is mounted.  slow fan, hot
alternator, burnt insulation, maybe fire.

Read up on the  alternator controller.  I found a reference:
http://forum.ssca.org/viewtopic.php?f=6&t=10915

and if  you read down a bit, one of the responses indicates it is in "The
12Volt Doctor's Practical Handbook".  That is a pretty useful book for other
reasons as well.

Regards,
Les H
On Thu, 2014-06-26 at 16:08 -0400, Julian Adams wrote:
> I have two electrical problems that have been resistant to my tinkering.
>
> 1. Low voltage at the helm.  I mounted a Garmin GPS unit (4308, I think
> the number is) ate the helm.   Every so often (typically when I need it
> the most) the screen goes blank.  I sent it back to Garmin for service
> at a cost of $500 only to receive a reply that there was nothing
> wrong.  A Garmin rep. told me that it was likely low voltage at the unit
> and sure
> enough when II measured the voltage it was 8-9 volts.   He suggested that
> it may be a bad ground. I replaced the cord and resoldered connections to
> no effect.   So if it is a bad ground where do I start looking?  I thought
> everything was grounded though the keel.   OK, maybe I am just showing my
> ignorance here?
>
> 2. This problem is unconnected to the first.   At the dock I can charge
> the batteries to the usual 13-14 volts (through shore power), but when
> we are cruising, and on the hook for several days the battery voltage
> steadily goes down to 10 to 10.5 volts (over say 3 -4 days)
> irrespective of how long I run the engine to top off the batteries.  I
> have removed the
> alternator and had it serviced.   I also have a unit called an alternator
> controller, made by a company named called "Spa Creek".   I have no manual
> for it; the company no longer exists so I can find nothing on the web
> about the unit.  It has a switch and a dial but no idea what the
> switch and the dial do.
>
> I would greatly appreciate some tips from on how to solve them
>
> Julian