Alternator charging

[Jim "SV Ohana"]

Always something new.  The usual process when I start the engine is the tach will lay there on zero for a few seconds, then you can here the engine bog slightly and the tach will jump to life.  Assuming this is the Alternator sensing the need for juce, etc.
Lately the tach bounces up and down and the volt meter wiggles in tune with the tach for about 4 min. then everything settles down to normal.  Turning on severl 12volt things doesn't seam to speed up the process.  This just started the last two times.
Sounds like a gremlin waiting to strike?????
It's a Balmar with external regulator. Batteries are all up and test OK.
Ideas??
Jim

[Ray Erps, #923. La Conner]

I recently installed the alternator recommended by Jim Moe and an ARS-4 regulator.  First time I turned on the motor, the tach didn't work and my heart skipped a beat.  That was the regulator doing it's job though, holding off on allowing the alternator to start working until the engine had a chance to run for one minute.  

Sounds like your external voltage regulator is doing the same thing.  One possible cause of the jumping voltage and RMP indicator needles might be that the belt is loose or glazed and starts chattering/slipping a bit when the alterator first comes on and is putting out maximum amps.  That's the first thing I'd check anyway because it's the easiest and there is no magic boxes involved.

By the way, the alternator recommended by Jim Moe worked great.  We used our fridge quite a bit on our recent vacation to Desolation Sound and the alternator/regulator combination kept our batteries in the best condition they have been in 20 years of fooling around in boats.

[Stu Jackson]

Jim,

Ray's right, loose belt is a good first idea.

Anytime anything jumps (other than me!) it's a loose wire (which, when I think about it, could also be me :)!!! )

Check the connections.  ALL of them.

I found a loose wire on my OEM alternator during our recent trip, tightened it, variations disappeared (I was fortunate enough to be allowed to stay).

Stu