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deltaten 04-30-2013 01:39 PM

Beta20 alternator vs battery
I had the alternator tested while the boat was in storage this winter. I re-installed it as it came out; one large wire to batt and two smaller wires with slip plug/spade ends. I marked them as to orientation before pulling.

This past weekend, while moving the boat home, I discovered that the batt wasn't charging. The batt was installed new several weeks ago. It read 12.54 volts. It was used to start the motor about 8 times when we moved from the well to the temp slip last week; 04/15-13. It seemed down a bit and was hard to turn over when we tried to get under way..seems I left the A/B/both/off switch on. The only item energized was the new depth finder; tho there *may* be other electrics aboard the have issues?!

Once started, I got a reading or two directly from the running alternator while underway. Both were close to or read as 13.5 volts. The GPS was showing only 10.5 or 11 volts!
Upon return to port, I hooked up shore power and ignited the charging system. Meter sez it's putting out 13.5 volts. Battery isolated sez 10.75-77 volts. After charging for several hours at , what supposedly was "bulk" charge..still only 10.77-79 VDC reading!

Charger in question is a (new) re-manf'd Pro charge 10a, two bank unit; tied together as per instructions for single batt. Alt is a std Kubota/Beta 40 amp.

Anecdotally, the marina guy sez that when they moved the boat from VA a yr and a half ago, his partner sez that the alt was not charging and the batt was draining!! Sounds ominously familiar?!?!
Could it be that the rat's nest of wiring left from the re-power job has hooked up something wrong? Could the two smaller wires be reversed? Having searched and read all morning; can someone point me in the right direction for a pictorial/wiring scheme for this particular alternator installation?

BTW... I see a full panel of instrumentation in my future ;)


tommays 04-30-2013 02:24 PM

Re: Beta20 alternator vs battery

It sounds like it looks a lot like this and if it does it may be faster and cheaper to deposit on scrap heap and make a clean start OR at least get rid of the really bad stuff

If it is a three wire alt then you should :) have a battery voltage sense wire (red ?) and a (purple ?) excite wire which become live when the key switch is on

deltaten 05-06-2013 03:58 PM

Re: Beta20 alternator vs battery
Well......I didn't go quite that far, Tommays; but I came close! ;)

Ended up *still* not having enuff juice. Started by completely discon'ing the bat and working from there with a hot-charged/toppped off battery. Straight hooked it to the engine and checked volts. Oooops! only 10.75. Discon'd and came back to near 12.48 (FROM ORIG 12.54).
I pulled the key/instrument panel and started checking wires..........

Seems some bonehead swapped out the original Beta?Kubota ign sw for a generic. Had the glow plug line set up on an "accessory" terminal that was always hot when keyed on. No wonder i couldn;t make juice!?! Damm'd plugs draw one helluva lotta juice! I wired a switch in the plug line and , wonder of wonders!!!!!!!!!!!!! it works.

Motor started up, ran better and for it's favor, got the oil changed ;) AFter all was settled, I re-hooked the DC pamnel and started tracing/checking switched lines. Most all the lites, tec work; just bad bulbs!

Now, on to other projects! :D

Thanx for the tip,

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