We are removing the alternator and havi any suggestions if the alternator is OK on 2000 Ford F-250 Super Duty

after about an hour drive today we stopped and the batteries were literally overheated you could hear the fluid rushing around in there and there's no juice no power would not start again.

Asked by for the 2000 Ford F-250 Super Duty
Check the alternator output at the battery post!!!!!..... Either one of the batteries!