Modify 12v Power Outlet: Always On

MCaesar

New member
Joined
Jul 17, 2011
Location
Wisconsin, USA
TDI
09 Jetta
I spent alot of time looking around the internet trying to find a way to change my 12v power outlet to always on. I start/stop my car quite frequently, and with the outlet being tied to the ignition, my phone's battery was not enjoying the constant power changes. I noticed others looking to accomplish the same thing but there didn't seem to be any How To for this specific modification, so I figured I'd put up a quick and easy guide on how to fix this yourself.
I did this on my 09 Jetta, so that's what the guide is based off of, but for those of you with other years/models, I would assume the general idea can be applied to you as well, the only difference would be the fuse locations, wire color coding, and the panels you'll need to remove to get access to the fuse box.

Tools required:
Torx driver (T20 was the size I needed for my Jetta)
Flathead screwdriver (or other device for prying)
Voltmeter
Needle-nose pliers
Fuse pin removal tool (not required, but makes things easier I would guess)

I didn't take pictures (didn't think about it till after everything was put together), but if anybody needs more specific/visual info, just let me know.

1. Remove fuse cover by driver door. Locate fuse 42 (verify for your car before proceeding using your car's user manual) and remove it.
2. Loosen fuse box by unscrewing top and bottom bolts.
3. Disconnect head-light switch (models may vary, however I believe most can be removed by setting the switch to the 'off' position, pushing in on the selector, rotating the selector clockwise, then pulling on the module. Use a flathead screwdriver to press the locking tab and remove the cable from the back)
4. Remove screw from inside of light switch module space. Should be located on the top side of the hole.
5. Pull off the trim above the steering wheel by the cleer plastic window for the tach/displays. This will give you access to a screw holding panel in front of fuse box. Remove this screw.
6. On the underside of the dash, by the pedals, remove the screws for the panel in front of the fuse box, remove the panel. (When removing this panel, there is a clip or 2 keeping it in place, use moderate force to get the panel off. Also there is a metal clip on the side by the fuse box, make sure that clears the plastic on the side, otherwise it will catch when you're trying to pull off the panel.)
7. Disconnect the dimmer switch from the panel and set the panel aside.
8. (This may be optional, not sure if this was absolutely necessary, I just did it because I wasn't completely sure how much access I'd have with it still in place) There is a black panel on the underside of the dash above the pedals (has the foot-illumination light, and the computer molex connector in it), remove the screws holding this up. You can just let the panel hang down, no need to disconnect the light or the computer connection.
9. Using a flathead, pry off the back cover of the fuse box. There 4 or 5 clips, so make sure they're all disconnected, don't force it.
10. The fuse box will not have much play considering the large bundle of wires connected to it, but maneuver it as best you can to work with the back-inside of the fuse box. Near the top left, in between the fuse box housing and the pink grid-box, there will be a small clip. Use a flathead to pry this open and pull the pink box down. This clip was a PITA, but once it's open the pink box will slide down a bit. The pink grid-box acts as a locking mechanism for the fuse connections, by sliding it down, you're unlocking them.
11. Locate fuse 42 (again, check your diagram before proceeding, make sure you're working with the right fuse for the 12v power outlets). On the back of this fuse there should be a red/black wire coming out from it. This wire is the hot for the outlet. Using the fuse pin removal tool (if you have it), or a small flathead and the needle-nose pliers, remove the fuse from the fuse box. What you will have is a small metal 'box' at the end of the red/black wire.
12. If you have electronic lumbar support, fuse 36 should work for you. Otherwise, locate fuse 35. Using a voltmeter, verify you have 12v going through with the ignition off (remove the keys completely just to be absolutely sure). Once verified, place the fuse you removed from 42 into 35.
13. Test the connection by putting the 20amp fuse into slot 35, then plug something into your outlet. You should be getting power with the car off.
14. Making sure to slide the pink grid-box back up to lock your fuses into place, reverse the steps from step 9 to put your car back to it's former glory :)
15. Enjoy

In the event your wire isn't red/black coming out of 42 (or appropriate fuse #), you will need to get access to the 12v power outlet's plug/wires. For my vehicle, I needed to pry loose the gear selector cover, which gave me access to 2 screws. Removing these screws allowed me to get to the underside of the plastic tray with the 12v P.O. My outlet is lit, so there were 3 connections/wires. The one closest to the lighting module is the hot for the light, the center is the hot for the outlet, and the 3rd is the ground. Your hot wire (most likely middle) should match the color scheme of the wire in the back of the fuse box for your 12v outlet.

This is my first post on the forums. Glad to be a TDI owner, and hopefully this helps others make this modification with less research time and guesswork than it took me.
 
Last edited:

Lug_Nut

TDIClub Enthusiast, Pre-Forum Veteran Member
Joined
Jun 20, 1998
Location
Sterling, Massachusetts. USA
TDI
idi: 1988 Bolens DGT1700H, the other oil burner: 1967 Saab Sonett II two stroke
Huh? They changed to a circuit 15? When?
My 1995 through 2005 VW all had hot (circuit 30) power outlets. No key needed.
 

Yacko

Active member
Joined
Jul 28, 2011
Location
Canada
TDI
2011 Jetta
Does anybody know if this is the same on 2011 ? I have the same problem with charging my cell phone.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
"I would assume the general idea can be applied to you as well, the only difference would be the fuse locations, wire color coding, and the panels you'll need to remove to get access to the fuse box."

Open her up and see whats what! I know VW didn't feel it was needed to include a fuse diagram, but i'm sure this will still be the same once you get the fuse numbers correct.
 

MCaesar

New member
Joined
Jul 17, 2011
Location
Wisconsin, USA
TDI
09 Jetta
Basically what 740 said. I don't have access to every year/model VW, so I don't know which of them even run off the ignition based power, and how each car is set up. I could assume that VW has the same setup for the 09-11 Jetta's, but who knows what they change each year.
The basic concept here is that it can be done (after a few days research I wasn't sure if it could be, because nobody had posted that they had or how to)
If you have a 12v power outlet that only runs off the ignition, then the basic theory is:
1. Get access to the back of your fuse box (again, assuming the dash fuse box, not the engine... but some models may have it in the engine for some reason)
The panels you need to remove may require some research on your part for your specific car, mine is based off the 09 Jetta, if that can apply to you, then lucky you, less research.
2. Once you have access, you have to track down the fuse you're currently on, and you have to find a fuse that will supply the continuous 12v. That's where the voltmeter comes in. Here's a picture to hopefully help clarify a bit

If you look below fuse 20/21, you'll see the large black cable going into a larger spade type bit. These large black cables are the power supply lines coming into the box, the smaller being the lines going out to the components. You want to test these large spade bits for a 12v reading even when the ignition is off. Once you have that, you can move your 12v PO fuse to connect to that supply. (I would recommend you see what other fuses are running off that larger supply line tho. If it's running incidentals IE radio, lumbar support, seat heating... it's a good supply to access. You don't want to place any extra load on a supply that's running important items on your car, I think you understand why)
3. After you've moved your fuse line to the new location, pop the fuse back in and test your outlet. Leave the ignition off and plug something in. Don't put your whole dash back together only to find out something didn't work right. It's perfectly fine to test it with the fuse box wide open, and highly recommended.
I put this thread up to keep others from getting discouraged when trying to attempt the same mod. I certainly was... there was little to no info on this mod, and for awhile I thought it was because it couldn't be done, or needed tons of car expertise to accomplish. I'm sorry I can't go out and get you a picture play by play on every car.
But I will tell you that I had fun figuring it out. Yes it was frustrating not knowing exactly what to do, but after a little fumbling and some wrong turns, I ended up learning things about my car I didn't know before. I'm also hoping this helps some people avoid a few of those wrong turns.
This mod doesn't take a rocket scientist, just some patience and basic knowledge.
 

graeme86

Veteran Member
Joined
Jan 14, 2005
Location
Brisbane, Australia
TDI
Not yet - fuel is too cheap! - 3.2 VR6 R32
On my Australian 2004 Mk IV R32 the ashtray power socket only works with ignition ON (due to a local Design Rule requirement)

On my car VW have just added a common N.O. Relay. When the ignition is ON the coil is activated and allows the battery power to the socket.

To disable this, you simply pull the relay and bridge the 2/30 and 8/87 pins with a suitable high current wire, then the socket is supplied power all the time.

Is there a similar relay in the later Mk V Golf/Jetta circuit, that could just be modified like this (i.e just remove relay and bridge two pins)?

Mk IV circuit is like this:

 
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kevin_in_idaho

Veteran Member
Joined
Sep 6, 2005
Location
Boise, Id
TDI
Returned 2012 Sportwagen DSG Pano White
I did a similar mod to my (US) TDI Sportwagen 2012. The issue really is that this circuit also powers the fan. So, if you aren't diligent about turning the fan off you'll run your battery down. The fan in position 1 is pretty quiet. The only option I see is to actually re-wire the cigarette lighter.
 
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