BCM Community

I'm rewiring the house batteries on my recently-acquired coach.  Seems like the PO went to a lot of trouble to not ground the house batts to the chassis at any point.  The only time they are connected to the chassis is when the solenoids to connect the house and coach batteries together is activated.

Is this correct?


Sent from my iPad using Tapatalk HD

Mine are. I added a solenoid to connect only the positive from house to start. I have worked on equipment that has used isolated electrical systems before, lots of wiring, but the design required it. Are you wanting to change it?

My system is grounded through the chassis, as most all 12v/24v DC systems are.

As many may know, the 4104 had a positive ground system.  While this is a pain to work with, it made the most sense to keep the electrons flowing outward and minimized galvanic corrosion.  I have a couple of 1957 Elgin 35hp outboards that are 12v positive ground that have no galvanic corrosion since the electrons were flowing out instead of bring the electrons and galvanic corrosion inward.  Good Luck, TomC

Electrons flow from negative to positive - that said, I'd love to know how this actually affects corrosion.  I have heard of battery type devices that are supposed to protect cars from rusting, but I couldn't figure out how the worked, so I wrote it off to marketing...   :o

Brian

This is way off the OP's topic but "galvanic corrosion" in the marine world is actually a misnomer - "galvanic erosion" would be a better term.  There are devices to protect boats from galvanic action using electrical potential and reference anodes but I don't see how anything like that could work to control corrosion on a car. 

Back to the original topic - if you already have grounds wired to all your 12 volt loads then, if it was me, I'd maintain that.  I don't get bent out of shape about using a chassis ground but it does concentrate potential failure points in the electrical system.