I tow my truck behind my motorhome using a Remco tranny pump with power supplied by the motorhome.

I want to disconnect the truck power while towing. I tried a battery disconnect on the neg cable but somehow there was still power. Right now I pull 2 fuses for the lights but there should be a way to disconnect all power without having to pull batt cables. Taillights, etc are all controlled by the MH.

Thanks
DICK