Did I kill my internal regulator/alternator? Battery selector switch use.

[Atcowboy]

Hi,

SHORT: does switching batteries with a perko switch while running - but never to OFF even accidentally - damage/kill alternators?

LONG:

1979 cape dory 27 with a ysm8 yanmar, and aftermarket direct replacement alternator of unknown age. But it is a 35amp with internal regulator, but the construction is not exactly like the yanmar manual so I believe it is an aftermarket unit just says OEM on it - no Nissan/yanmar/Bosch.
12 months ago my engine alarm started squeaking at low rpms. I assumed it was oil pressure, pooped my pants, and chased that. It was not that.
As time wore on the charge light began to dimly flash with the squeak, sometimes. Then eventually it started brightly flashing while running but without the alarm. I was still getting amps (all the amps, it seemed to be working just fine) so I just ignored it.
Out of curiosity once while it was charging I changed the perko switch from ALL where it always lives, to 1 and to 2 with the engine running. I noticed my batteries weren't equally charged, one able to take many more amps. I started to make this checking for equal charge using the perko switch a daily part of my bulk-charge ritual. Then the solar would try it's best to top them off.
Eventually the alarm was going off regularly, racing the engine would shut it off. The alarm light blew, I thought that was the cause, then it stopped charging all together but I was still able to manually flash the field to get it to start charging/regulating. Then well into a bulk charge run after working down from about 37 amps to 26 it got hot and smelly and went from 26 amps to 0 and hasn't worked since.

So, I would say it was obviously dying for a while. But did I hasten it's death? Does switching between the batteries momentarily unload/disconnect the alternator similar to switching it off? Should I not do this with the replacement alternator?

- AT

[HeywoodJ]

Perko battery selector switches are built “make before break” when switching between 1-All-2, so if you never pass through Off a battery is always connected and it shouldn’t cause damage to the alternator.

Your initial symptoms sound like a corroded connection to/in the engine panel, but that, too, shouldn’t kill the alternator.

[Atcowboy]

Originally Posted by HeywoodJ

Perko battery selector switches are built “make before break” when switching between 1-All-2, so if you never pass through Off a battery is always connected and it shouldn’t cause damage to the alternator.

Your initial symptoms sound like a corroded connection to/in the engine panel, but that, too, shouldn’t kill the alternator.

Thank you for the information on the perko switch.

Performing some engine maintenance today and getting a close look at the wiring loom, I can imagine it may have something wrong with it. There is some not yanmar wiring to connect the alternator. The connections at the panel itself looked OEM, and in great condition. I shall be trying to make the alternator side more reliable when I get the new one in the mail.

- AT

[smac999]

if the swtich is old you can change it to be sure. but a working swtich should not cause any issues.

[Cadence]

Originally Posted by HeywoodJ

Perko battery selector switches are built “make before break” when switching between 1-All-2, so if you never pass through Off a battery is always connected and it shouldn’t cause damage to the alternator.

Your initial symptoms sound like a corroded connection to/in the engine panel, but that, too, shouldn’t kill the alternator.

Saves me typing.

[seabreez]

Originally Posted by Atcowboy

Hi,

SHORT: does switching batteries with a perko switch while running - but never to OFF even accidentally - damage/kill alternators?

LONG:

1979 cape dory 27 with a ysm8 yanmar, and aftermarket direct replacement alternator of unknown age. But it is a 35amp with internal regulator, but the construction is not exactly like the yanmar manual so I believe it is an aftermarket unit just says OEM on it - ..... But did I hasten it's death? Does switching between the batteries momentarily unload/disconnect the alternator similar to switching it off? Should I not do this with the replacement alternator?- AT

I do not know about the different switches, however your question about switching while running should never be done with an alternator. A momentary disconnect or reduced contact will destroy or weaken the diodes and eventually will nor rectify anymore...