65 amp and 55 amp alternator voltage regulator

manoa matt · Post by **manoa matt** » Mon Nov 19, 2007 8:09 pm

I got a 78 with a 55 amp Bosch alternator. I also have a spare 65 amp Bosch alternator.

I would like to upgrade to the 65 amp unit.

The external voltage regulator on the 55 amp one is good and has a lot of life left on the brushes.

The external voltage regulator on the 65 amp one is good, but the brushes are at the end of their life.

The question is: Are the voltage regulators interchangeable? Can I put the 55 amp voltage regulator on the 65 amp alternator?

So Cal Mark · Post by **So Cal Mark** » Mon Nov 19, 2007 10:18 pm

when you say "external regulator" do you mean the vr on the fenderwell or on the back of the alternator?

manoa matt · Post by **manoa matt** » Mon Nov 19, 2007 11:54 pm

On the back of the alternator. Black box 1 inch X 1 inch X 2 inches

I have YET to check if the regulators have the same serial/model/reference numbers

mbouse · Post by **mbouse** » Tue Nov 20, 2007 9:02 am

I believe those should be classified as internal regulators. External regulators being mounted to the firewall, or fender well.