Alternator arrhythmia?

[steneck]

Folks,

I have a 92 PS 34 in Maine. Recently the engine developed a fluctuation that is very easy to hear but it does not register changes in rpms. I see on my DC panel, however, that the charging needle is bouncing in rhythm with the audible fluctuations.

I have a BALMAR 100 amp belt driven engine alternator equipped with a MAX CHARGE SMART regulator. Might it be some sort of alternator-regulator problem? I will confess to sailing much more than motoring so the batteries are often lower they they probably should be.

Any thoughts out there?

Bob Steneck

[adamowens]

Possibly belt slipping on the alternator? When you say charge needle,
I assume you are talking about the voltmeter?

Adam
PSC 31 Journey

[ralopata]

It sounds like a regulator problem, however, I'm not sure what make or model the "Max Charge Smart" you're referring to is. Over the years, we have replaced two solid state regulators-- Balmar Max Charge -- after they have apparently been "cooked" by the heat in the engine compartment. In our case, the engine rpm fluctuations began only after the temperature in the engine compartment got hot enough to start affecting some part of the regulator that was beginning to fail. This made the problem somewhat maddening to solve because the system charged normally when it was started up, and would only start to fluctuate after about 20 minutes at cruising rpms.

Since the regulators are solid state -- black boxes to me -- I'm not sure there's any way to check them or repair individual parts. Each time, I've replaced the whole unit, a simple process -- it mounts on the engine compartment wall and has a fairly simple wiring harness. A mechanic with more electronic knowledge may be able to tell you some way to check the unit before replacing it.

Roger Lopata
JUNO -- PSC 40 -- #46

[SVArgo]

Search the forums for "hunting" one of the common names for your issue, that may provide some better information.

[steneck]

Good ideas from several folks. I don't think my problem is the belt, but I will check it. The fluctuations are seen on my voltmeter.

In my case, the fluctuations occur as soon as I turn the engine on and tend to go away once the batteries are charged.

I never heard of "hunting"... does it refer to the charger looking for the right voltage?

I appreciate you help.

Bob
PSC 34 Alaria