when Powerdrive charger is plugged in it clicks but no amps on ammeter. All connections have been checked and are good. Batteries all read 8v. Pack voltage is 48.6v. I checked voltage at charger receptacle and only reads 36v. Receptacle connections and fuses are all good. i reset obc and receptacle reading is same as pack voltage 48.6v I can plug in charger and try to charge and nothing but a click. I take charger out receptacle and voltage reading at receptacle is back to 36v. Any idea of what is wrong?? It has done this intermittingly in the past, now it won't charge at all.