Wherein we wire the house and car batteries together. The main question was how to get cable access to the car batteries.
Ford, in their wisdom, decided to store a ~6.7 million Joule energy source (AKA the pair of stock AGM batteries) under the driver's seat .
I had first thought to punch one hole low down in the seat base. But, the base is slanted (insert political joke here.), and the steel is very hard. I could not get a starter hole drilled.
I found that if I slightly widened one for the covered slots higher up, it would fit a cable and grommet.
So that's where the cables are routing.
I suspect those slot are there in case you have flooded batteries, and need some venting. They are covered inside the base with a plastic sheet.
I added lugs to the seat end of the cables, and roughly determined their placement in the seat base.
Then I fed the other end of the cabled in between the inner and outer side walls. I punched a hole in the inner wall and used a grommet.
Continued running the lines toward the back. When I neaten things up, I will be filling the holes in the rib shown below with expanding foam to keep the cables away from the metal edges.
I found a convenient hole to get back to the inside world.
Wired in the BlueSea ML-ACR relay. (That's the VSR in the last post's block diagram).
Attached the cables to Annie's batteries and neatened up a bit.
Put the seat base back together, and called it a day.
There are two reasons for this interface. One is to allow Annie's alternator to charge the house batteries as we drive. The other is in case Annie's batteries die. I can switch the ML-ACR on and use the house to jumpstart Annie.
I had planned on adding a fuse at Annie's batteries, in case something went awry between the two battery sets. However, the BlueSea instructions explicitly say not to do that if you want to run as a jumper. So, I am not going to do that yet. Also, since it's a real pain to access the under seat battery junctions, if I do add a fuse, it will probably be near the ML-ACR.
Finally, the ML-ACR has a remote control switch. I'm still deciding where I want to install that. It may go in the control/monitor panel that I'll be putting in above the fridge.