Your post is a little confusing. First, I suspect the chassis batteries read 10.7 VOLTS, not amps.
And you do not mention replacing or changing wiring for the house 6 VDC batteries. Please confirm with a digital voltmeter (start under $10) the reading at the house battery bank. Red lead to the cable running from a positive terminal to the inverter. Black lead to the cable running from a negative terminal to the inverter. If it does read 19.4 VDC, something is VERY WRONG. Yes, batteries could be hooked up incorrectly or inverter/charger malfunctioning.
