I just replaced my alternator with a Premium Bosch ALO752X. I made sure the battery was fully charged before hooking everything back up and starting the car.

Within about 5 minutes of starting, at idle speed, the metal back-half of the alt (close to the black plastic cap) gets so hot I can't touch it without risking a burn. I also smell something "new" getting very hot. When I turn off the car, it begins to cool down. The pos battery lead will become warm, the neg lead remains cold.

It only occurs when the engine is running (and thus the field is excited). I don't think it's a short in the battery. I don't see any missing insulation/hot spots on the main alt cable going to the starter. The only other thing I can think of is that the alt itself doesn't have a good ground. The bolt on the backside attaches it to the engine. The other two bolts mount to a bracket. . . . . perhaps I left something loose . . . . . .

Any ideas?
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1998 V70 T5 124Kmi; Previous car: 1985 SAAB 900T, 254kmi