No 12V Power After Lithium Battery Wiring Upgrade

[stateofidleness]

Hi all! I have a 2011 Zoom 18ft camper that I am in the process of upgrading to a lithium battery… turning into quite the project lol! I upgraded the Wfco converter to a Wavlink lithium one, moved battery from tongue to interior (about 4 ft from panel), and used 6awg from battery to fuse panel board.

In doing this, I’ve managed to be able to charge my battery, but no 12v works. I climb under and find a metal junction box (pictured), that I’m assuming was my ground as well.

To support the bigger amp charging, I upgraded to 6awg wiring, but the original wiring is 10awg. I’m not sure how to tie in the wires in that junction box while also upgrading the wiring.

Do I need to introduce fuse blocks somewhere?

 

[Mark_K5LXP]

If all you did was move the battery and trade 10ga for 6, it should work as before. Did it work before? If so, then you miswired something. A meter will reveal pretty quickly where your hot or ground is open.

Mark B.
Albuquerque, NM

 

[bigbAZ]

The ground (negative) is that double lug bolted to the frame (circled in red). I also see what looks like the connections for the running/brake/signal lights in those crimp caps. Not sure what all that is under the big blue wire nuts, do the original #10s go to that box?

 

[stateofidleness]

The ground (negative) is that double lug bolted to the frame (circled in red). I also see what looks like the connections for the running/brake/signal lights in those crimp caps. Not sure what all that is under the big blue wire nuts, do the original #10s go to that box?

View attachment 2488383

Yep original 10’s go to that box. My thought was to run a new 10awg (30amp fused) from battery to that junction box (positive), and from battery negative terminal to that ground lug on frame. Would that do the trick?

 

[Seilerbird]

Photograph the crap out of it before removing anything.

 

[bigbAZ]

Yep original 10’s go to that box. My thought was to run a new 10awg (30amp fused) from battery to that junction box (positive), and from battery negative terminal to that ground lug on frame. Would that do the trick?

I'm guessing your original negative landed on one side of the double lug then another run went from the second lug to the fuse box. Your lights aren't working because they use the metal on the RV for negative, so what you need is a jumper from any point on the negative system to one of the lugs on that double lug. It should be sized to the load. If the old one was a #10 and you are not adding load then #10 should work. If you haven't torn it out yet, you can probably just tie the old #10 into the new #6 at any convenient point using a split bolt of the correct size (they are marked with wire size ranges).

 

[Kirk]

I’m not sure how to tie in the wires in that junction box while also upgrading the wiring.

That box looks to me like it is where the cord that connects to your tow vehicle is connected to the RV wiring. If you look closely, you will see that the ground wire pointed out by bigAZ is not inside of that box.

 

[stateofidleness]

That box looks to me like it is where the cord that connects to your tow vehicle is connected to the RV wiring. If you look closely, you will see that the ground wire pointed out by bigAZ is not inside of that box.

Seems so, but also has the main original positive battery cable in it. I’m thinking I’ll run new negative cable from battery to that original chassis ground, and a new positive from battery to that junction box and tie it in where the old wire was wire nutted in.

 

[bigbAZ]

Seems so, but also has the main original positive battery cable in it. I’m thinking I’ll run new negative cable from battery to that original chassis ground, and a new positive from battery to that junction box and tie it in where the old wire was wire nutted in.

If you already ran your new #6 from the battery to your fuse panel the only thing you need is a jumper from negative to the frame. No need to mess with anything else. Try it with a alligator clip jumper cable first and see if the lights work.

 

[stateofidleness]

If you already ran your new #6 from the battery to your fuse panel the only thing you need is a jumper from negative to the frame. No need to mess with anything else. Try it with a alligator clip jumper cable first and see if the lights work.

Oh hmm. The original red battery cable underneath isn’t connected on with end anymore now though. So I’d need to wire that back in to get the trailer lights and all that to have power right? Instead of pulling out the original 10awg and connecting it to the battery, I was gonna run a new 10awg and leave all the stock wiring underneath intact.

 

[OldWEB]

That box looks to me like it is where the cord that connects to your tow vehicle is connected to the RV wiring. If you look closely, you will see that the ground wire pointed out by bigAZ is not inside of that box.

If you look more closely, we are not quite sure where it goes...

... at the moment.

 

[stateofidleness]

If you look more closely, we are not quite sure where it goes...
View attachment 2488622

... at the moment.

That black one is the one coming off the chassis ground lug. Comes from tongue to chassis ground, then into the box in that pic.

 

[OldWEB]

So I’d need to wire that back in to get the trailer lights and all that to have power right?

The camper outside lights will be powered from the tow vehicle, that is the directional, park and brake lights.

 

[OldWEB]

All the "hot" wires for the camper DC-powered items come from the fuses in the breaker/fuse panel... you have the DC "+" feed going in there from the battery/converter, so they all have the positive to them. If none of the DC-powered items work, they do not have their "-" return back to the battery, the electrons need to go full circle.
So in my unit, almost all of the returns, most are white wires, and they are located behind my breaker/fuse panel, I need to remove the drawer above to access them. They are mostly under ONE LARGE Marrette cap and connected to the 12VDC negative "-" there. Your wiring most likely is different, but you need to find those white return wires and give them the "-" from the battery.
Your one pic of the box has some white connected to the one black.

 

[Mark_K5LXP]

I would want to know why things stopped working after I messed with them. Adding 'extra' wires may not be the best solution. Identify the problem THEN the solution.

Mark B.
Albuquerque, NM