Appreciate everyone’s responses – that’s what makes the WTW forums so great. Camper frame grounding has always been a puzzle to me, and I suspect to a few other folks as well. A few follow-ups to clarify:
- Thom, the additional breaker at the truck end of the DC-DC charging circuit makes good sense, thank you. It will also allow the truck bed connection to be de-energized when the camper is unloaded, a good thing.
- Vic, my DC-DC/MPPT charger is the Renogy model RBC30D1S, with M8 (5/16”) terminal posts, so I can crimp matching rings to any gauge wire. Seems like nice flexibility.
- Agree that 6 AWG wire would be sufficient for the 30A DC-DC run to the truck battery, and may offer easier connector type options at the truck bed wall. I’ll also need to figure out how to best run a 16 AWG positive ignition sensing wire through the same (or additional) connector and forward to an ignition fuse tap. I’ll check that out, but all suggestions are welcome.
- Craig, your comment “left the entire FWC 10ga wiring in place” made we wonder if you had both the 10ga and 6ga wire pairs energized to the fuse panel. Am I understanding correctly?
- I did a quick test to verify that no factory 12V load device depends on the frame for a ground connection. Disconnected the factory wires from the fuse panel, and temporarily replaced them with [fused positive] and negative wires from their respective buses. All load devices operated properly (LP/CO monitor, inside lights, exterior patio lights, roof vent fans, furnace).
- Vic, the camper grounding question appears to be relevant only if the camper is unloaded from the truck, correct? That is, when unplugged from the Anderson connector that is already grounded to the truck frame? For the unloaded case, it seems like my options are:
1. No changes, use the existing factory 10 AWG wires and frame ground. Deal with larger voltage drop than desired to more sensitive device demands such as furnace, fridge and tablet/phone chargers.
2. Keep the existing 10 AWG frame ground wire, but only from the negative bus (disable the frame ground wire to the fuse panel). Run explicit 8 AWG positive and negative wires to the fuse panel.
3. Option 2, but replace the 10 AWG frame ground wire with larger (__ AWG) wire. Requires opening up the front wall to access the frame.
4. Disable the existing frame ground wire. Deal with loss of ground connection when unloaded from truck in some other manner.
All thoughts welcome!