wolfe10 wrote:
Not sure I understand how the signal terminal connected to the house battery (sounds like an odd signal source to me-- I would have expected it to be an "ignition hot" source and usually off the chassis battery) could have 14 VDC and yet the large lug to the house battery could have 12.5 VDC.
If neither large lug is receiving alternator output (14 VDC)with the engine at high idle, the problem may be in your alternator or between the alternator and solenoid.
I think the signal terminal is getting power from the alternator. The top lug is getting power from the house batteries, which are not being charged, and the lower lug runs the dash lights etc, like you stated
