Originally Posted by NorCalVanDwlr
Need help on how to deal with my House Battery - Is it a Factory Ford mount, or a conversion company addition?
Would love to see Wiring Schematic to work on it
This is mounted under Passenger side twin doors
Yes that looks like the stock Ford AUX battery and it is where it is normally located on the outboard side of the passenger frame rail. There are four bolts that hold that in place. These bolts, two on each side screw into two very convenient clipped-to-the-frame nut holders. Two of the bolts must be removed and the other two, one on each side, can be left threaded but loose. This allows the box to be lifted and slid off the bolt heads (and to make re-installation a bit easier). The box will drop down but should be held up by the limiting cable mounted to each side of the box.
Now the box can be tilted to reveal the plastic cover attached to the battery box. Two bolts remove that. Inside should be a Group 65 battery (about the only battyer size that will fit in there. The wiring at this location is very straight forward Positive and Negative cables. Remove those cables making sure to protect against the positive cable grounding out to any metal as it is directly connected to the battery in the engine compartment.
There is a small head long shaft bolt that secures the battery clamp. it is located in the box down the outboard side of the battery.
As to the rest of the wiring schematic for the aux battery - someone else can chime in with where to look for the separator relay, etc.
Dual Battery Threads:
And this should be helpful as well with wiring schematic: