Power riddle on my 'new to me' slide in camper

[djmase]

I just picked up an old school Sun-Lite slide in camper. The PO gave me a wiring harness that goes from the + and - of the starting battery back to the bed. At the starting battery end the ground is going to the frame and the + is going to the + plus battery post and it has an inline fuse in place. At the bed end of the harness there is a three a plug for connecting to the camper that has three wires, it looks like a typical four place trailer plug, but only has three wires in and out. On the bed end there are also three wires that connect to the deep cell in the camper, two for + and one for - (again, according to PO).
Here is the issue: the power in the camper will not work unless I have the fuse in place thus allowing the starting battery and the deepcell battery to drain. If I pull the inline fuse out, whole system goes down. Moreover, I pulled the deep cell out, but made sure the two + leads that are supposed to go to the deep cell remain connected, the system keeps going. SO, it seems like the camper is only pulling from the starting battery. Any ideas on why this is happening?

Ideally, I just want to run the camper off the battery inside and keep it totally disconnected from the truck system. I build a small system to go from deep cell to + and - on camper harness and that did not work.

I am an electrical idiot, any help would be appreciated.
Thanks!

 

[dwh]

If you ran all the camper loads to the camper battery and they didn't work, and they do work when connected to the truck battery - then it sounds like what would happen if your camper battery was dead.

There's no mystery. If the camper loads are (properly) connected to the camper battery they should work whenever the camper battery has a charge - whether or not it's connected to the truck battery.

If the camper battery is disconnected from the truck battery, and the loads don't work, but the loads DO work fine when connected to the truck battery, then the problem has to be the camper battery.

Only other thing I can think of is maybe (not likely) a grounding problem.

 

[Gooseberry]

It could be a fuse on the camper battery if its not dead. You will want a seperator to not cook your truck battery something like a sure fire.

 

[djmase]

If you ran all the camper loads to the camper battery and they didn't work, and they do work when connected to the truck battery - then it sounds like what would happen if your camper battery was dead.

There's no mystery. If the camper loads are (properly) connected to the camper battery they should work whenever the camper battery has a charge - whether or not it's connected to the truck battery.

If the camper battery is disconnected from the truck battery, and the loads don't work, but the loads DO work fine when connected to the truck battery, then the problem has to be the camper battery.

Only other thing I can think of is maybe (not likely) a grounding problem.

Camper battery and second test battery both test well, so I am thinking it mist be something wired incorrectly in the harness.
I am going to pull the harness off the starting battery and run it to deep cell directly and see if that will make it go.

 

[djmase]

If you ran all the camper loads to the camper battery and they didn't work, and they do work when connected to the truck battery - then it sounds like what would happen if your camper battery was dead.

There's no mystery. If the camper loads are (properly) connected to the camper battery they should work whenever the camper battery has a charge - whether or not it's connected to the truck battery.

If the camper battery is disconnected from the truck battery, and the loads don't work, but the loads DO work fine when connected to the truck battery, then the problem has to be the camper battery.

Only other thing I can think of is maybe (not likely) a grounding problem.

Camper battery and second test battery both test well, so I am thinking it must be something wired incorrectly in the harness.
I am going to pull the harness off the starting battery and run it directly to deep cell directly and see if that will make it go.

*Dumped the one out of Pop-up as this seems like a more accurate place to put the question.

 

[dwh]

Ahh. Well I wished you'd quoted my reply in that other thread, since I don't remember what exactly I said.

Anyway, I seem to recall you said something about the camper battery not being grounded. That would certainly cause the problem you've described.

 

[djmase]

Ahh. Well I wished you'd quoted my reply in that other thread, since I don't remember what exactly I said.

Anyway, I seem to recall you said something about the camper battery not being grounded. That would certainly cause the problem you've described.

Ended up just scraping the old harness, it was a mess. For now I set up a simple stand alone unit (86ah) for the camper lights, all led. Per my Calcs (in a perfect world) think I'm looking at 4.8 days of solid run time.
When I get some time I'll probably go with the first option you posted so it'll charge while I'm rolling. At least we won't be in the dark at Yosemite!

Thanks for the help!