The manual says, that the alternator connection is an INPUT. But I can measure voltage there if nothing is connected. Is this normal? I would expect that if this is an input, that the voltage should come from the alternator or the battery. Am I wrong ? Or is this an output-connection as well ?
The start battery connection is an input only.
What voltage are you seeing at the input post without the start battery connected?
If you connect a small load to it, does the voltage drop to 0?
FET-based devices can "leak" a small amount of voltage sometimes, but there should be 0 current behind it, thus why I suggested testing with a small load to see if the voltage immediately drops to 0.
