Sporadic Sterling Alternator regulator problem.

Ric

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8 Dec 2003
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I have had a sterling alternator regulator on my VP MD2020 for ten years of reliable service.

Recently the alternator alarm started sporadically sounding at anything below around 2000 rpm. If I increased the revs, the alarm would stop, then I could usually reduce back down to idle without it sounding again. I immediately guessed that the alternator belt needed tigthening so did so - but problem persisted.

I then noticed on my NASA battery monitor that the Sterling regulator was not doing its job - the volts and charging amps on the NASA were just normal alternator regulator performance. On checking the Sterling, all the lights were flashing showing that it was in failure mode.

So I shutdown engine and restarted - everything went back to normal - engine could run at idle without alarm, and the Sterling started up its ramp start. But as soon as it ended its ramp start, the lights started flashing again and alternator alarm sounded again.

Any suggestions before I don the hard hat and write to Mr Sterling?
 

halcyon

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20 Apr 2002
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I have had a sterling alternator regulator on my VP MD2020 for ten years of reliable service.

Recently the alternator alarm started sporadically sounding at anything below around 2000 rpm. If I increased the revs, the alarm would stop, then I could usually reduce back down to idle without it sounding again. I immediately guessed that the alternator belt needed tigthening so did so - but problem persisted.

I then noticed on my NASA battery monitor that the Sterling regulator was not doing its job - the volts and charging amps on the NASA were just normal alternator regulator performance. On checking the Sterling, all the lights were flashing showing that it was in failure mode.

So I shutdown engine and restarted - everything went back to normal - engine could run at idle without alarm, and the Sterling started up its ramp start. But as soon as it ended its ramp start, the lights started flashing again and alternator alarm sounded again.

Any suggestions before I don the hard hat and write to Mr Sterling?

Check brushes and slip rings on alternator could be worn / sticking brushes or dirty / worn slip ring.

Brian
 

pvb

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I then noticed on my NASA battery monitor that the Sterling regulator was not doing its job - the volts and charging amps on the NASA were just normal alternator regulator performance. On checking the Sterling, all the lights were flashing showing that it was in failure mode.

So I shutdown engine and restarted - everything went back to normal - engine could run at idle without alarm, and the Sterling started up its ramp start. But as soon as it ended its ramp start, the lights started flashing again and alternator alarm sounded again.

Any suggestions before I don the hard hat and write to Mr Sterling?

Double-check that the red wire from the Sterling regulator is securely attached to the battery.

Do you have a splitter diode? If so, check that it's OK.
 

Birdseye

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9 Mar 2003
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Doesn’t sound like quite the same problem but I had difficulties with the sterling charge controller on my 2030. The problem turned out to be that they charge controller was making the alternator work hard which was of course its purpose. However this caused the alternator to overheat and And the solder on the diodes in the alternator to soften giving intermittent dry joints. So I got intermittent alarms. On my boat the engine is very tightly packaged by the woodwork.
 
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