Alternator overcharging on Cummins diesel

[Evidence]

Hi ttmott,
Thanks for those comments.
The fluctuating AC possibly simply mirrors the fluctuating DC value.
I'm thinking the closed circuit (short) between the sensor terminal (No.2) and the Batt connection is a certain indicator that the Alt is bad- despite being new.
Is that (short ) also a symptom of a failed rectifier bridge?
Also that result argues its pointless installing this alt on the port engine to help determine if its the cause of the high output.
Your comment about the battery, appears improbable bc the same 2 x12V wet cells service both engines - and do not cause a prob with the port engine.
Thanks
Cheers
E

On reviewing my documentation of symptoms re, what I termed “alternator overcharging’, I was struck by me recording, many times that my 24.6V batteries were being charged at ~70 Amps at a votage below 24.6 - which of course is impossible. When I was taking the clamp meter readings I did not record the polarity - reasoning -at the time that, bc the alt was new - of course it would be charging!! Now I realise that, rather than the batteries being recharged they must have been shorting - presumably via a failed rectifier in my brand new Delco. I have now removed the alt and taking it for repair tomorrow.

Cheers all

 

[Evidence]

On reviewing my documentation of symptoms re, what I termed “alternator overcharging’, I was struck by me recording, many times that my 24.6V batteries were being charged at ~70 Amps at a votage below 24.6 - which of course is impossible. When I was taking the clamp meter readings I did not record the polarity - reasoning -at the time that, bc the alt was new - of course it would be charging!! Now I realise that, rather than the batteries being recharged they must have been shorting - presumably via a failed rectifier in my brand new Delco. I have now removed the alt and taking it for repair tomorrow.

Cheers all

Woops -- not rectifier, I understand the symptoms indicate a failed regulator,