bad voltage reulator,kill the batteries?

[racerx179]

I've got a 99 f250 and just replaced both batteries and the guy checked the stating system and then the alternator and said it was bad. he said i sholud unhook the batteries at home so they don't get drained by the altternator. Is this true ?

[JSchuricht]

It's possable. If a diode failed in the alternator it can draw power when the truck is off. Get a multimeter with a amp setting, connect it in series between your battery and the ground while the other battery is disconnected. Disconnect the alternator and if the draw goes way down then it's bad.