Time to switch to a 10Si alternator. Bolt on replacement. No more voltage regulator. You have a 10DN. No reason to continue with it.
Watch out for careful drivers!!! I'm away on an ego trip. Will be back on Feb 30. I'm not an Auto Mechanic, but I play one on TV. I charge $0.02 for every opinion and I take Paypal. Plan B is always better than plan A, by definition.