This alternator was completely rebuilt under warranty by Balmar (I can supply RA invoice proof if interested). They said the diodes overheated. We had two XT-170 installed on our Yanmar marine diesel, the other installed with the same Balmar charge controller was not even hot when this one malfunctioned, so it was some manufacturing problem. I’m keeping the one I still have as it has been perfectly reliable with many sea miles over the past year and a half. I’m selling this one because it is now in the United States for the repair and too expensive to ship it half way round the world to. Replacing it with a 48V alternator to match our lithium batteries.