Always On 12v Power for Topper/Camper Lighting

I want to add some LED lighting to my camper shell.

I've successfully disable the cargo light and put it on an individual switch to stop throwing light on my sleeping family when I want to get into the front of the truck at night while camping.

Next I'd like to add some lights inside the camp shell, as well as around the outside.

Is there a power source at the back of the truck that's always on, or will I need run a line from the battery?

 

My 7 pin trailer plug has an always on hot pin.

 

Mine too, it's spliced and goes into my bed/ cap for power.

 

Ah ok. I assume it's AUX 12v:

 

Take the key out and confirm with a multi meter, but that should be it.

 

No dice so far. 12v AUX doesn't appear to be hot.

2006 DC Limited with factory installed tow package.

 

Sometimes there is a fuse for this circuit, and it may not have the fuse installed, happened on my 2005 sequoia the first time I towed.

Might be something to look at.

I guess I should ask does it have power there when key is on?

 

2015 TRD Off Road- Mine only has power when the key is in on or acc position. No power when truck off keys removed

 

Any guesses on what the fuse/circuit is?

 

Why not just run a hot back there? Sure it's a bit of a larger project, but worth it IMO.

You could add a small fuse block under the hood and pull from that to the bed. It's a nice way to future proof for accessories down the road.

Or pull a larger AWG to the rear and put a fuse block in the back. That will give you options back there.

Or do both?

I find it nice to have individual circuits for each accessories, instead of tapping into existing circuits. Much easier to diagnose when things inevitably go weird.

 

I wanted to determine if there was a possibility for something quick and easy. Got a lot of other projects going on right now and just wanted to add some lighting to the camper shell.

If it's not easy, I'll pull 10g wire up to the battery, like you said, for future options.

 

Yeah - I hear that.

I would imagine there is a hot associated with the 7 pin... I know a buddy of mine pulled one to add a USB plug in the bed of his DC. I had initially assumed it was from the 7 pin, but now you have me second guessing.

 

This is what I would do. Mainly because once it's done right you will never have to mess with it again and can easily add whatever depending on the size of the fuse block. Also you should probably buy a jump pack, if you don't already have one, in case you drain the battery all the way down and can't start the truck.

On a side note I power all my bed stuff from the solar system so it is completely isolated from the truck, it's been working out great. Recently went to Florida and the truck was parked for 10 days. Fridge, tent, lights, all powered off the solar the whole time. Never started the truck until the day we left.

 

How many watts of panel do you have? That's impressive. Just one battery??

 

I do the same as @Wallygator. I currently run a 95ah battery (happened to already have it) in the bed with a MPPT solar charge controller and a 100W solar panel on top of the topper. Used to run a 100W flexible panel on top of my tri-fold tonneau cover and that worked great before I installed the topper. Also have it rigged up with an AC-DC charger and DC-DC charger so I can charge it overnight if necessary from the wall or while driving if there's no sun.

 

I also have a 2006 DC with the factory tow package. I am almost certain that the 12v in the 7pin is ignition.

I just ran an 8awg from my battery, along my frame to behind my driver side tail light. Behind there I mounted some cheap little 6 port fuse block and use that to power anything that I need inside my camper.

 

Now that's interesting. My factory 7-pin is spliced running into my cap and is hot at the plug. I'm curious if there's a difference between ours somehow or if there's something I'm missing.

 

I've got the factory tow package on my 03 AC. I'll test for constant hot and report back...

 

FWIW,I just checked my Tundra plug, looking at it from the rear, my pin # 3 on this diagram is hot with the truck not running and key off. 2001. I was looking at my install notes from 20 years ago, and I have the center pin labeled as an "extra" circuit.

 

Ha! We're all going out and checking out trailer plugs.

My '03 with factory trailer wiring (per the build sheet) is wired as indicated in the diagram above. #4 aux 12v is only powered with the ignition on. #3 is powered with the taillights on, regardless if the key is in.

The PO ran a fused wire from the battery back to the cap for lighting in the bed.

 

It's a Renogy 160 watt panel.

 

This is beginning to make me wonder if there is a 2 position, 3 pin fuse located somewhere. There can’t be this much variation.

 

I think mine is wired the same as yours. I'm going check all the pins tomorrow, truck running, ignition on, not running, and key out and will post the results.
Edit for update:
I looked at my plug this morning, with a multi-meter in hand, and it is wired the same as this diagram. Just FYI.

 

Did you ever figure it out? I have the same truck, I added lights to the shell bed today and taped pin #4. It only powers on when the key is the ignition.

going to run a wire to the battery most likely.

 

Just a friendly reminder to install a fuse in-line somewhere close to the originating power source.

I was doing some work on my truck recently, and found that a prior stereo installer ran a 0awg wire from the battery to the amps with NO FUSE. The problem I was diagnosing was a loose wire at a distribution block.... if that had come out and grounded, or worn through the sheathing? Yikes.

 

Got it. The wire has a fuse but it’s next to the on/off switch in the bed of the truck. Should I move it next to the battery?

 

As close to the battery as possible.

 

You always want to fuse or breaker your power leads as close to the power source as possible. If your fuse is at the bed/switch, what happens if you ground out in the cab?

When we were entering cars in IASCA competitions back in the day, IIRC the regulation was to have a fuse within 18" of the battery for all power leads elsewhere.