For you guys that have hooked a 24 volt alternator to your house batteries, where have you actually tapped into the 24 volt from the alternator?
Simple. From the 24 volt positive cable that leads to the start batteries. I connected mine at the load side of the disconnect switch. It then goes to a 250 amp cont. duty solenoid /relay (combiner) to the house batteries. The start batteries also have an Intelletec 'BigBoy' latching solenoid disconnect (so I don't have to get out and flip that big switch to disconnect) that's installed after the manual disconnect. If I have a bad start battery, I turn the manual disconnect off, turn on the combiner solenoid, and turn on the 'BigBoy' solenoid. This give me the flexibility to 1) charge house batteries from the alternator either manually, automatically (when the alternator's actually putting out), or keep them disconnected 2) have an emergency 'jump start' from the house batteries if needed and 3) keep my start batteries charged by occasionally combining the two sets when on AC and the charger's running.