2002 9400i overcharging?!?!

Ok ive dealt with undercharging trucks a million and a half times not but what happened today was a first. Today the only international in the fleet was out on deliveries. I get a call from the driver telling me his voltage gauge is acting weird and bouncing up (maxxing out) and back to normal earlier this morning he had a toasted fuse for his blower motor (when i say toasted i mean hot enough im typing this with a blister on my thumb and index finger, anyways he brings his truck to me after the delivery to show me the gauge going crazy as a back up i check the batteries and alternator and at a high rpm idle they are charging at 16+ volts and at a regular idle at 15.5 15.6 volts. I replaced the alternator three weeks ago with a rebuilt one but i noticed today it charges 135 amps and i know the original charges at 110 amps am, since its internally regulated am i correct in assuming the alternator is the source of the overcharge and may be bad or is there something else i should look at?

 

I sm actually replacing the batteries now currently waiting for my other two to arrive. The current batteries are only 2 years old so they were on the eclipse of being changed anyways.

 

So i replaced the batteries still charging up around 15.3 at an idle so removed the alt and took it down were i got it to have it "tested" and the guy is going to swap out the regulator for another and see if that cures the issue before swapping for a different one all together.

 

Lol yes im checking with a dmm, over the last two years ive found the gauges in internationals to be highly inaccurate. Ive been taking the measurements at the alt and the battries. Got the alt back and now its measuring 14.6 accross the studs and at the alt. So hopefully the problems solved.

 

Well once the squirrel cage is back on the blower motor it will be ready to go and just open up space for another. Have a 06 Freightliner Columbia and dumpbed trailer to get suited up and ready for running again.