Glitchy Regulator ?

[farhorizonsail]

had an issue come about while motoring the other day:

about 2 hrs into the trip i began to hear bursts of buzzing coming from my engine compartment. the bursts lasted about 1-2 seconds a piece and were being generated every few minutes. they were accompanied by jitters on my engine gauges- oil pressure, temp, and volt meter (tack is disconnected right now)...

i am in the midst of an electrical overhaul and did not have use of my heart link battery monitor. i did manual voltage checks on my house bank and starter battery and found their voltage levels to be normal...

my thought was that the regulator was glitching out and sending surges of power through the system...

has anyone heard of this before?

i am running a 1979 perkins 41.08 with a pretty new 50 amp alternator. the regulator is probably 8 yrs old and is the balmar knock off (by west marine maybe?)...

both my house bank and starter batteries are all new this year and i'm stressing that they received several hours of unregulated high rpm charge during the 5 hr voyage.

any thoughts?

[osirissail]

One idea, sounds like a slipping alternator belt. It will make different noises depending upon the belt style and of course when the alternator loses rpm's the engine instruments fluctuate - usually the tachometer but other also can depending upon the source of their power. An increase in load caused by something turning on inside the boat will start the slippage. Then the item shuts off and the alternator returns to normal operation.

Look for glazed surfaces on the belt and check the amount of tension by depressing the belt in the middle of its longest run. Also check the various pulleys it runs over for loss of friction.

[GordMay]

Greetings and welcome aboard the CF, farhorizonsail.

[osirissail]

Originally Posted by farhorizonsail

. . . has anyone heard of this before?

i am running a 1979 perkins 41.08 with a pretty new 50 amp alternator. the regulator is probably 8 yrs old and is the balmar knock off (by west marine maybe?)...

both my house bank and starter batteries are all new this year and i'm stressing that they received several hours of unregulated high rpm charge during the 5 hr voyage.

any thoughts?

Forgot about that part of your questions. First, an 8 year old anything electrical is not new but most probably well worn or been subject to corrosion damage by salt water atmosphere environment.

What do you mean by the underlined part above? How high did the charging voltage get? If above 14.5 volts then definitely the regulator is faulty (or the wiring between the regulator and alternator). Also faulty wiring and connections between the alternator and/or regulator and the batteries or a diode isolator (it may be bad) can cause the alternator to be loaded down or then unloaded which will cause noticeable engine rpm fluctuations and power supply problems.

First, I would suggest examining the belt and then also examining all the connections and wires between the regulator and alternator and battery(s). Wire terminal corrosion is very common in older boats.

[farhorizonsail]

responding to osirissail (am i not supposed to post replies to this thread? sorry, i'm new...):

my concern about the batteries receiving unregulated charge is, i think, unfounded... it stems from an incident that took place when i first got the boat where a series of missteps lead to the boiling of my starting battery...

i did manually check the voltages of the batteries (both house bank and start) and found them to be normal. i just get paranoid when i can't monitor the amperage output while motoring, which i usually do because i don't trust my regulator (i'm in the midst of an electrical refit that will include its replacement)...

there were no fluctuations in rpm during the buzzing episodes...

i will check the belts and the connections for corrosion... thanks so much for welcoming me to the forum!! i see myself spending a great deal of time here now!!

[donradcliffe]

The jitters on your gauges might indicate something is arcing, perhaps an intermittent short, but probably not a slipping belt. Or maybe something else in the engine compartment is buzzing, like a bilge pump or a fuel booster pump. Its hard to speculate what's going on unless you can catch it in the act.

[delmarrey]

Originally Posted by donradcliffe

The jitters on your gauges might indicate something is arcing, perhaps an intermittent short, but probably not a slipping belt. Or maybe something else in the engine compartment is buzzing, like a bilge pump or a fuel booster pump. Its hard to speculate what's going on unless you can catch it in the act.

Ditto! Check all your wire connections around the motor, especially at the starter, battery, alt, and any terminal blocks/connectors.