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I wanted to share with you all a small mod I did today that add something to the Disco that is much needed, an “always-on” 12v outlet in the load space area.

As you are probably aware, the 12v outlet in the rear of the vehicle is, normally, only on when the power is on. Which means after you cut the engine you have about 3 minutes before it cuts out. Rendering it pretty much useless while camping, or for running something like a fridge.

But I have resolved that problem, using just a small piece of wire and quick disconnect.

So while researching this problem I came across a wiring diagram that noted there is a vestigial wiring harness under the load deck, behind the styrofoam spare tire surround. This wiring harness is intended for some sort of European trailer hitch or something. But importantly, it contains a “hot” 12v pin wired to a 15A fuse.

You can access the harness by removing the load deck, the left side foam piece closest to the tail gate, and the plastic kick plate on the tailgate, which is just held in by clips and pulls right out with a good tug, with no risk of breaking pins. Against the tailgate you’ll see 2 large harnesses, 1 grey and 1 green. The green one is connected, but the grey one is just sitting there empty. The grey connector is this vestigial trailer hitch connector.

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Now, what’s great, is that the GREEN one, right there? That goes to the loadspace 12v outlet!! How convenient.

Onthe green connector the black wire with green strip goes to ground (you can see where it’s grounded in the lower right corner of the photo above, along with a bunch of other black/green wires.) And the brown wire with yellow strip is a aux power line, that is hot only when the car is on, no good.

Now, looking in the grey connector, you’ll see a purple wire coming in the back, it is the 2nd pin from the left on the “short” row of connectors.

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Testing this with a multi-meter you’ll be able to confirm that it is indeed “hot” and reads ~12v when the car is fully turned off. This is our target.

You can connect to this pin using a 7/64” Female Disconnect. Through trial and error I figured out this size, it is PERFECT. Holds securely. I recommend a fully insulated version of this connector, just to be 100% certain it can’t move and cause a short, but the risk of that is minimal. It is just as secure as a factory plug, I had to use a pliers to pull the test one off.

So, all you need to do is put one of these connectors at the end of a short 16 gauge wire, I made mine about 12” long, but this was VERY excessive. I might redo it with just a 6” wire.

At the other end of the wire, use some sort of disconnect. I used “bullet” style disconnect, because for whatever reason I really like them, I usually use them.

So connect the female end to the other side of your make-shift jumper, that way if it does come loose you don’t have a naked 12v hot wire rattling around.

Then just sip the brown/yellow wire going into the green harness from the right. I snipped it about half way down, and attached a male connector to the side coming off the harness.

For safety sake connect the jumper to the green harness wire FIRST, then to the pin in the grey harness.

TAKE PRECAUTIONS, THE PIN IS CARRYING A HOT 12V CHARGE.

Final product should look like this.

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,
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and voila, that’s it. You now have an always-on 12v outlet in the loadspace.
 

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Cold beer and dead battery? Handy mod 😊 if you use a vacuum cleaner or a tire pump
 

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Discussion Starter #3
Cold beer and dead battery? Handy mod 😊 if you use a vacuum cleaner or a tire pump
Common sense should always be used, of course. I wouldn’t plug anything into this that didn’t have a low-voltage cut-off, like any good fridge.

For the time being I did this mainly so we could recharge electronic devices and power packs in camp without running the truck.

Eventually this will get a 500w or 1000w ”generator” like GoalZero or Jackery, with a fridge hook up to it.
 

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I'm interested in this for the same reasons as you, charging battery devices while the vehicle is parked. Have you had any issues with a flat battery yet? My Disco is 2 years old and we now start to get low battery warnings just from repeated but not excessive use of the tailgate when the car is parked overnight at a campground.
 

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Discussion Starter #5
I'm interested in this for the same reasons as you, charging battery devices while the vehicle is parked. Have you had any issues with a flat battery yet? My Disco is 2 years old and we now start to get low battery warnings just from repeated but not excessive use of the tailgate when the car is parked overnight at a campground.
I haven’t stressed it yet, but I’m about to spend 2 weeks overlanding across Colorado and living out of the Disco, so we’ll see.

However, I did JUST replace the battery, just 2 weeks ago. I was getting low battery warnings constantly as well. FORTUNATELY, the “low battery” warning and countermeasures, like cutting off auto start/stop and disabling the power lift tailgate, but in LONG before the engine isn’t able to start.

When the dealership tested the battery they were getting just under 11v max, and the truck still wasn’t having any trouble starting. That voltage is well below the automatic cutoff for the inverter I’ll be plugging in, and way way below the cutoff for any fridge, even the most agressive settings.
 

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I haven’t stressed it yet, but I’m about to spend 2 weeks overlanding across Colorado and living out of the Disco, so we’ll see.

However, I did JUST replace the battery, just 2 weeks ago. I was getting low battery warnings constantly as well. FORTUNATELY, the “low battery” warning and countermeasures, like cutting off auto start/stop and disabling the power lift tailgate, but in LONG before the engine isn’t able to start.

When the dealership tested the battery they were getting just under 11v max, and the truck still wasn’t having any trouble starting. That voltage is well below the automatic cutoff for the inverter I’ll be plugging in, and way way below the cutoff for any fridge, even the most agressive settings.
Well, I'll be keen to hear how you went when you get back from overlanding :D I loved Colorado when I visited! Feel free to share your setup with fridge/inverter too - I'd be interested to see how you configure things for overlanding.

I'll be looking to replace my battery before my next remote camping trip as it could easily end up flat with no one around to jump start from. For the time being I just have a big Anker power pack that I charge everything from.
 

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Well, I'll be keen to hear how you went when you get back from overlanding :D I loved Colorado when I visited! Feel free to share your setup with fridge/inverter too - I'd be interested to see how you configure things for overlanding.

I'll be looking to replace my battery before my next remote camping trip as it could easily end up flat with no one around to jump start from. For the time being I just have a big Anker power pack that I charge everything from.
My battery is on its way out as well so my local dealer tells me. Stop/start hasn’t worked for over 12 months now but I don’t really mind that. However, I’ve purchased a Projecta Power Hub (Battery box) with a 120ah AGM battery. The hub has heaps of outlets and a 300w sine wave inverter built in. Bought this purely to run my Engel 40ltr fridge. I also bought a 200watt solar blanket. Over the 6 days I was away camping, the solar blanket kept the battery charged all day. Overnight the fridge used around 10% of the battery power. I ended up only needing to charge it on the solar blanket once in the week. The fridge was plugged into the 12 volt power socket of the car while we were on the road.
 

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Discussion Starter #8
My battery is on its way out as well so my local dealer tells me. Stop/start hasn’t worked for over 12 months now but I don’t really mind that. However, I’ve purchased a Projecta Power Hub (Battery box) with a 120ah AGM battery. The hub has heaps of outlets and a 300w sine wave inverter built in. Bought this purely to run my Engel 40ltr fridge. I also bought a 200watt solar blanket. Over the 6 days I was away camping, the solar blanket kept the battery charged all day. Overnight the fridge used around 10% of the battery power. I ended up only needing to charge it on the solar blanket once in the week. The fridge was plugged into the 12 volt power socket of the car while we were on the road.
Yep, that’s pretty much my plan as well, but with a Jackery or GoalZero lithium battery pack instead of one with a car battery.

I’ll probably get the battery pack and fridge setup before my next adventure. I’m heading out for Colorado for 2 weeks tomorrow, and I’ve already dumped a frankly irresponsible amount of money into this trip and the truck.

I think I’ve gotten my girlfriend addicted to the idea of overlanding though, so I have her fully support.
 

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@Spectre08 Thanks for sharing! Looks useful. I'm headed to the Sierras, White Mtns and maybe Death Valley next week. I might try to do this before I go. It's pain to have to keep pressing the start/stop to keep things running/charging.

Good luck in CO!
 

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I just use a 25ah lithium power pack (kickass I think). It will run my 50l fridge for about 13 hrs. Uses the car 12v whilst running and I’ve got a 50W solar blanket for when it’s not. The blanket can fully recharge the power pack whilst running the fridge during the day while stopped. $450 for the power pack and solar blanket all up. And totally portable
 
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I just use a 25ah lithium power pack (kickass I think). It will run my 50l fridge for about 13 hrs. Uses the car 12v whilst running and I’ve got a 50W solar blanket for when it’s not. The blanket can fully recharge the power pack whilst running the fridge during the day while stopped. $450 for the power pack and solar blanket all up. And totally portable
That's really useful to know! I already have a 26Ah power pack - might have to think the solar blanket to complete the setup!
 

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Right on! I actually did the same thing myself, but a little differently, and posted about it a couple years ago. Great minds think alike!
 

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Right on! I actually did the same thing myself, but a little differently, and posted about it a couple years ago. Great minds think alike!
yes! I saw your thread, but all that fishing for wires behind fuseboxes and such didn't look very fun, that's how i ended up using the wiring diagrams to figure out that there was a harness back there with a live wire running right next to the wire running to that outlet.
 

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yes! I saw your thread, but all that fishing for wires behind fuseboxes and such didn't look very fun, that's how i ended up using the wiring diagrams to figure out that there was a harness back there with a live wire running right next to the wire running to that outlet.
Nice! I forget about that harness being there to tap in to. Is that the harness that goes to the trailer wiring and supplies the 12V power to the 7-pin?
 
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