26 replies to this topic

[ElGigante]

I have a new to me 06 Grandby shell. All the aftermarket stuff runs off the battery bank. Heater, extra outlets, one side light. However the roof mounted lights and the fan which are factory seem to only run if I hook up my truck to the wiring harness.

Does this mean that they will be running off my starter battery?

I will eventually be rebuilding the entire inside but for now we were just going to live with it as it is then see what our family really needs. I do not want to have the fans and overhead lights draining my battery though.

Can I check that with a multimeter? Will the Amps coming from my trucks battery change if I fire up the fans and lights?

Anyway I am more of a carpenter than an electrician but I figured this would be an easily answered question.
I searched the threads here and on FB to no avail.

[Vic Harder]

Welcome to the cult ElGigante.  Sounds like the person who added the aftermarket stuff did not want to play with the existing electrical and left it as is.  What that means is that the connection to your truck does two things:

1) It allows the truck to try (it doesn't do a good job of that) and charge your camper battery while the truck is running

2) It powers the running lights (if you have them)

3) It powers the basics of a shell, the fan and overhead lights.

 

If you can follow the wiring after it comes into the camper, it will eventually lead to a smallish 30A thermal breaker, and from there to a battery separator, which is designed to keep your two systems (truck and camper) from totally draining each other.  When either end is receiving a charge, it is supposed to connect the two systems together so that they can both charge.

 

Before saying much more, can you confirm all of the above?

[ElGigante]

Thanks so much. This makes sense for sure. I will look tomorrow. And see if I can follow the lines. The problem is the owner before built cabinets and put lots of the wiring behind and the cabinet for the battery is a bit of a rats nest.

Thanks again for taking the time. I’ll take a bit of mine look and get back to you. I do feel better now though. It did seem weird that the two were separated and that FWC would allow for the starter battery to run the campers basic functions.

[Wandering Sagebrush]

Hi ElGigante, welcome to WTW.  Vic nailed it.  A possible quick way to determine if the truck is charging the battery is to check camper battery voltage with the truck off, then again with the truck running.  There may be a switch that connects the charging circuit to the battery.

[Old Crow]

You might take a look at this post for help in your wire-tracing efforts.  You may be able to see the yellow wire running along the cabover floor in the left-front of the camper and then down into a cabinet.

 

Tech Tip / Service Bulletin (Camper to Roof Wiring)

 

I'd also look for yellow at whatever fuse panel(s) you have.

 

Also- there's a truck-to-camper wiring diagram in this post to help you see what wiring to the battery separator often looks like.

 

Steps for wiring truck pdf

Edited by Old Crow, 05 February 2023 - 03:58 PM.

[Machinebuilder]

I wonder if the camper had a battery from the factory.

[Jon R]

I wonder if the camper had a battery from the factory.

I’m thinking it didn’t.

[ElGigante]

Sorry guys. Life’s getting In The way today. Taking the kids disc golfing. Hopefully time to check later.

[Wandering Sagebrush]

Sorry guys. Life’s getting In The way today. Taking the kids disc golfing. Hopefully time to check later.

No worries, have fun with the kids.

[ElGigante]

Ok. I had a few mins to look at the wiring. The main wire in from the plug goes immediately behind the original particle board. You can see that in picture 1.

Also I’m picture 1 you can see smaller gauge orange and black wires leading to a switch and a 12v outlet. These appear to be stock but moved by the previous owner to outside a cabinet he built.

You can see that in picture 2. In this picture the to 12V the previous owner must have added. It works even when not hooked up to truck and is run by the larger gauge red and white wires at the top of picture 1 to the battery bank. Going through a fuse box that the previous owner installed to run the propane heater and a water pump. See picture 3.

There is one set of yellow and black wires that comes from behind the carpet and goes behind the front hinge that looks factory and no doubt powers the fan and two lights on the roof. This only works when plugged into truck harness. Picture 4.

It looks to me like the previous owner either moved the battery that came with the camper or that the camper came without a battery. The new system he put in looks like it is set to only work of shore power and solar charging. Both of which he put holes In The camper to install exterior plugs. See pictures 5 and 6.

Seem like I will need to redo the whole thing at some point and In the mean time just get a portable solar panel to charge batteries for now.

I will check the voltage of batteries when hooked up to truck without truck on. Then turn on truck and check again. Hopefully this will let me know if a connection still exists between the two. If not I’ll have to assume the starter battery in my truck is running the lights and fan? Gosh I hope not lol.

The next step after that would be to start removing some of the after market cabinets and such to get a better look behind the paneling at the stock wiring.

Thoughts? Thanks in advance.

Ps. Sage I assume you’re the guy who put up the YouTube videos last year of your build out. I liked them. Was gonna model our design of yours. We are ultra lighters so we can do without most of the stuff people put in their bulldogs these days. But I probably will over build for 2 lithiums and a decent inverter. Putting 200-400 watts on the roof at some point down the road.

Likely I’ll keep the propane heater (if it works well at altitude)