[johnnywal]

Just a thought, could the alternator problem be a result of the battery reaching the end of its useful life.
The problem seems to be occurring when the GC is a couple+ years old and if demands are being made on the steering electric pump and the battery doesn't have enough amp output, the alternator would be asked to put in the difference.
I realise the alternator should be designed to cope with this, but maybe if all is not 110%, the diodes fail under the constant load.
I don't know what amps the pump motors draw but it must be pretty substantial.
I could be totally barking up the wrong tree, but as I said it was just a thought!!
Have any of these alternators gone with a new battery in the vehicle or only older ones, even if they seem good batteries??