Draining the batteries

When I got my 2016 RAM and went to have the camper put on, they checked to see if the RAM had and issolater.
Nope, so I had them put one in.

Otherwise, what happens when you pull the power cord from truck to camper... maybe it defaults to the Truck, dunno, but I would think if camper wasn't connected to the truck during that time, it might go to the camper batteries..

Just thinking out loud here... also, just in case, an inverter will draw power if on, might check that for power loss...

Hope that helps a little...

There was no isolator in either my 2006 GMC truck or my Outfitter camper, and yes, if the truck sat for over a week it didn't want to start. I had an isolator installed, which solved this problem. Tom McCloud

Interesting problem.... Have you tried unplugging the camper from the truck to see if the issue is in fact caused by the camper??
It doesn't make sense to me that the camper batteries are remaining fully charged and the truck is dead unless there is a wiring issue.
If there is no ignition relay that shuts the power off to the 7 pin connector there would only be one way I could imagine the camper draining the truck batteries without draining the camper batteries... Is there is a battery switch somewhere in the camper that is wired to allow the camper to use only the trucks power while the camper batteries are shut off??
If there is constant power to the 7 pin connector (with no ignition relay) the camper should draw from both systems and the 200 watts of solar should be more than enough to keep everything charged.

mikakuja wrote:
Interesting problem.... Have you tried unplugging the camper from the truck to see if the issue is in fact caused by the camper??
It doesn't make sense to me that the camper batteries are remaining fully charged and the truck is dead unless there is a wiring issue.
If there is ignition relay that shuts the power off to the 7 pin connector there would only be one way I could imagine the camper draining the truck batteries without draining the camper batteries... Is there is a battery switch somewhere in the camper that is wired to allow the camper to use only the trucks power while the camper batteries are shut off??
If there is constant power to the 7 pin connector (with no ignition relay) the camper should draw from both systems and the 200 watts of solar should be more than enough to keep everything charged.

Cannot see the camper draining the truck either. I also would say unplug truck and camper and let it sit and see what happens. Could be a huge phantom draw in the truck.

Check the specific gravity in the truck batteries . A bad cell in one of the batteries will do that . On GM' s you need to install the 40a fuse for the charge line to camper , is it installed ? Have the truck batteries behaved properly in the past ? An isolated or continuous duty solenoid would be a good idea .

I just install two new batteries the mechanic thought maybe bad cell so replaced

200W of solar I can't imagine that the batteries would be anything but charged. :)

Maybe it was faulty truck batteries after all?

My old 97 would drain the battery camper or not. I installed a knife switch on the battery which got used every time I wanted to use the truck.

I guess I should have said it drained the new batteries also

Typically GMC/Chevy does not have a battery isolator- charge line always hot.
Camper plugged in it will drain truck.
That said, the campers batteries showing charged not sure-

"Mechanic' should be able to check parasitic drain of truck if excessive (though should have been able to load test a battery?).

Pull the fuse in the engine bay fuse box for the trailer battery charge line if you cant easily get to camper plug. If you have manual should identify, #2 "I think" but verify.

IF somehow and kinda of a stretch, camper is disconnected from its batteries,
but plugged into truck it might use truck for power.
More questions than answers

My truck sits weeks at a time with no problem. Most times I just leave it plugged into camper and let my solar charge truck. Both truck and camper are AGM batteries so solar is not doing any damage to truck batteries