I have no explanation for the 32V reading.

Here is another idea. Take the alternator off the airplane, and take it
to an automotive shop that has an alternator test bench. For example,
the Pep Boys store about 1/2mi from my house has one. They can spin it
up, apply field current through a rheostat, apply a load, check its
output current and ripple. If it has a blown diode, they should be able
to tell you. You will have to make up some story about why they cant
sell you an "exchange"

Take your core, and either have it repaired, o/h, or trade your core
for one that is already rebuilt by a FAA repair station. If there is
nothing wrong with yours, you can work with your mechanic to reinstall
it on the aircraft.

I have had the Ford Prestolite alternator in my 182 develop "open
diode" ripple. In my case, the one of the stator wires became
disconnected from the diode stack due to vibration. It was "repaired".
I got charged about $100, and it was returned with a yellow tag..