Dash voltmeter showed 15.9 prior to replacing alternator. Alternator has internal voltage regulator. Have not checked for possible code after most recent incident but it was so quick I doubt it registered.
Voltage reading at dash with new alternator 13.9. Current fault P 0883 ( TCM Power Input Signal High ). Voltage spiked briefly to 16 today after coach was running for 3 minutes. As you suggest, something other than alternator is probably causing problem, plan to have Freightliner look at it and will let you know what they find.
Thanks
Patrick