HELP!! Alternator putting out 36V at idle!!

[66charger73]

I was going out the other day and noticed the voltmeter was sitting at or a little below 12V and i started to smell something burning. I have a 120 Amp denso alt that has been in the car for 2 yrs no problem. the fuse i had put in the alt feed wire had burnt up and caught fire. I checked the power output and it was 70V at high idle and 36V at normal idle. Swapped out voltage reg, original 60A alt, and still same problem. This must be an electrical problem somewhere else. Need help before i lose the car in a fire! It's a 73 with electronic ignition if that helps. Thanks for any info in advance.

[Nacho-RT74]

mostly sure rotor shorted out inside alt, or somehow of short inside... thats my guess

[charger Downunder]

The positive of the alt check that it isnt shorted to earth there should  be a non metalic washer behind it.