stevekat

I recently replaced an alternator on an R3 when the front bearing started making noise. I sourced a low mileage used unit and the replacement went well. I also replaced both belts and the idler pulley on the AC belt while doing the work.

However, I am curious if anyone knows what the difference is between the Series II and Series I alternators.

TeamRX8

iTrader: (25)

According to the Service Highlights manual, the output was improved, but from what I see the max 100A output was unchanged. So it may be an efficiency improvement with the internal components. As far as I know they’re different in that regard and distinguished as being different between S1 and S2, but my expectation would be that they’re still interchangeable. I don’t know it for certain though and could be wrong.

Did you swap with another S2 alternator or an S1?
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ASH8

Yes by Part Number they are different, I had one new here for S2 but sold it.

The difference ?, as Alternators also have the Regulator internally and are way smaller than when they were a separate unit back in the 70's and 80's
perhaps the difference is in the Regualtor stats in regard to the S2s come out of factory with a larger LA Battery over S1?

TeamRX8

iTrader: (25)

the max charging output is the same on both, so it must be something else.
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stevekat

Yes, replaced with another Series 2 unit from eBay, alleged from a 30K mile vehicle.

Would be interesting to know if they are interchangeable.