Looking for a little help here. The batteries on my JD 310A won't hold a charge. I charge them (2 - 6 volt batteries run in series and they test at 6.3 and 6.5 respectively) however, when I let the machine set for for a few days and go out to start it, it barely cranks over. My mechanical knowledge (not vast) says its a faulty alternator however, when I took the alternator to the local alternator/starter rebuild shop, they bench tested it (in my presence) and it tested out just fine. The alternator has a built in voltage regulator and it too (according to the technician) tested fine. The tech tells me there is another sensor somewhere in line in the system that tells the alternator the batteries need to be charged...I thought that was the function of the voltage regulator. If there is another sensor in line in the system, does anyone know where it is located so I can test or replace it ? If not, any ideas of what the issue may be ?
Lets start from scratch, disconnect the ground cable from the batteries, charge the batteries up fully. Then let them sit a few days, hook the ground back up, and see if it starts. Easy enough?