DIY 12v Constant Power Outlet MOD

peiphil

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Nov 7, 2012
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Tignish PEI Canada
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2005 passat GLS TDI and big old Dodge Cummins TDI
I just done a 2014 Passat using a jumper.
It had a black 645 relay that was in the same position as the green one pictured above.
The jumper goes from top to bottom where pins 3 and 5 on the relay used to plug in
 

pparks1

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Joined
Aug 13, 2013
Location
Westland, Michigan
TDI
2013 Passat TDI SE
So you pulled the relay out, then built a piece of wire with 2 spade connectors and then plugged the spade connectors into where 3 and 5 went. The relay can then sit in your glovebox until you decide you want to remove your mod.

This right?
 

vw_norm

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Jul 22, 2012
Location
Hawaii
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2012 NMS TDI SEL Platinum Gray w/moonrock
Your jumper wire should be at least 12 gauge wire to match the fuse rating. Smaller wire can overheat, get hot and become a potential fire hazard due to current flow, depending what you got plugged in. This would be the case if an inverter were used or other high amp draw device. Most car electronics normally have a low amp draw.
 

pparks1

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Aug 13, 2013
Location
Westland, Michigan
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2013 Passat TDI SE
Your jumper wire should be at least 12 gauge wire to match the fuse rating. Smaller wire can overheat, get hot and become a potential fire hazard due to current flow, depending what you got plugged in. This would be the case if an inverter were used or other high amp draw device. Most car electronics normally have a low amp draw.
The only thing I plug into the lighter adapter is my cell phone and the kids portable DVD player.
 

PaulB

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Aug 6, 2000
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Oregon, USA
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2013 Passat TDI SE M6
Your jumper wire should be at least 12 gauge wire to match the fuse rating.
I'd be concerned also about the way the OP handled the problem, by jamming a spade connector inside the relay. High current may cause the "contacts" to oxidize and burn, which eventually will heat things up until the relay melts or burns or starts a fire.

The spade connectors for the jumper should be the same quality and size as the relay's. The wire should be bent to the correct shape before adding the spade connectors, and they should be soldered.

Looks like 14 guage stranded wire should work for a 30 A fuse though.
http://www.powerstream.com/Wire_Size.htm

If you are going to leave something not correct for that current in there, at least change the fuse for a lower current rating.

OK I just took the relay apart and see the OP is using the stock contacts. That is better but I still wonder about making them work with something other than the stock coil. I was not comfortable with modifying this relay.

I tried some spade connectors but had none thick, wide and long enough to make a good solid contact like the relay blades do, so i nixed that also. Back to the stock setup for me (sigh).

The manual states that each plug uses up to 120 watts. I have two of them, so for me anyway that is 20 A. It's unlikely to be drawing that much from both at the same time, so I think a 10A fuse might be a good idea here, if you are going to do these mods.
 
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MB2VW

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Jun 8, 2000
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Lighthouse Pt., FL USA
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2015 Passat SEL,
An Easier Way Perhaps

The other day, I needed to run an ignition switched 12v source to my visor area to support a Dash Cam. I chose to use crimp on spade quick disconnect lugs to tap the fuse block:

I used a male to tap the fuse block:

I came across this thread this AM, and I thought I would suggest that you could achieve the same results by using the same approach.

I didn't execute this, but I did some measurements for confirmation.
1. Pull F42
2. Fabricate two short wires, each having a Male Spade Quick Disconnect Lug , and Female Spade Quick Disconnect Lug. Heat shrink Female side.
3. Attach two wire's females to 30amp fuse pulled out in step #1
4. Insert wire #1 Male into Point #1 (labels for points on diagram are just below actual point, or fuse contact)
5. Insert Wire #2 Male into Point #6 (load side of F42)

The nice thing is that you can quickly undo this mod, if you need to.

For what it's worth!
 

jrm

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Jul 24, 2013
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Oregon
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2013 Passat SE with nav (totaled)
Wonder if this would work on the JSW to have the 110v outlet always hot? Be great for camping trips when you need to charge things.
Running the inverter would drain the batt when not in use
 

Dave_D

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Jun 9, 2003
Location
Gaithersburg, MD, USA
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2015 Passat Titanium Beige six speed manual & Jetta, 1999.5, Tornado Red
Has anyone done this mod on a 2015 Passat six speed manual? I pulled the drawer to gain access to the relays, but in place of the "644" relay I find a "645" relay. I also don't find the lock tab and have thus far been unable to pull the relay to jumper it.

Can someone else with a 2015 six speed manual confirm that this mod is still possible? I want constant power to charge various equipment as did the originator of the thread.

Dave

PS: I stand corrected, as I see post #31 in the thread shows the 2014 had a "645" relay as well. My problem is now I was unable to get the relay out even depressing the lock tab as directed. Perhaps I lack the proper tools to accomplish this.
 
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bustNfuel

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Joined
Sep 7, 2002
Location
Raleigh, NC
TDI
Sold: 13 Passat SEL TDI
I performed the RelayEctomy today.


After looking inside the relay housing, I determined the best long term way to do this was the jumper method as pictured.










...I see post #31 in the thread shows the 2014 had a "645" relay as well. My problem is now I was unable to get the relay out even depressing the lock tab as directed. Perhaps I lack the proper tools to accomplish this.

I used a small flat-blade screwdriver and wedged it between the relay housing and the tab, which needs to be bent outwards away from the relay. While doing so I also gently pried on the relay and used my other hand to pull and wiggle the relay until it popped out of the socket.
 
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HowieE

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Joined
Dec 1, 2012
Location
Princeton NJ
TDI
2015 Passat stick shift
I am about to try the relay jumper method of getting constant voltage to the 2 12 volt receptacles in my 2015 Passat. When I opened the panel that cover the relays I find just what you have posted.

However when I look at a site claiming to diagram the 2015 Passat they show something different in the location you mention for the receptacle relay. They claim the 2 relays in that location controls the glow plugs for the diesel.

https://fuse-box.info/volkswagen/volkswagen-passat-b7-2011-2015-fuses-and-relay

Scroll 40% down the page to the Fuse Block Diagram and you will see what I refer to. My question is is there any chance the single relay that you mention for the 12 volt receptacles can also be for my glow plugs. That might explain why it is a 30 amp fuse. If so I am dead in the water for the jumper method.
 
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bustNfuel

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Raleigh, NC
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Sold: 13 Passat SEL TDI
I looked at the link you posted, and it is confusing.

On my 2013, the relay I removed and inserted the jumper did work to turn on my 12v outlets full time. No trouble codes regarding Glow Plugs. Maybe the 2015 is a bit different, or you're looking at the wrong set of relays?


I suppose you could remove the relay, and see if you get a Glow Plug trouble code. If not, with the ignition still on 'run', see if your 12v outlets are still working or not. If they're not working with the relay removed, then you should be all set to jumper as pictured above.
 
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HowieE

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Dec 1, 2012
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Princeton NJ
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2015 Passat stick shift
For some reason I can't post a picture to this forum. The picture shows as I create the post but displays as text when submitted.


That said my relay lay out looks the same as yours and I will attempt the jumper when it stops raining.


Thanks for the help.
 

HowieE

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Dec 1, 2012
Location
Princeton NJ
TDI
2015 Passat stick shift
Well I got the relay out with some fabrication to a pair of needle nosed vice grips. Thought I was home free. Testing the circuit before installing the jumper I find 12 volts on pin #1 of the relay socket even with fuse 42 removed. That causes question as to where the fuse is for the lighter receptacles and what is fuse #42 really controlling.


I don't just want to install the jumper without some idea as to how it is fused.
 

HowieE

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Dec 1, 2012
Location
Princeton NJ
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2015 Passat stick shift
Correction.
The voltage I am reading when the fuse is removed is on pin #3, one side of the contacts.
 

bustNfuel

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Sep 7, 2002
Location
Raleigh, NC
TDI
Sold: 13 Passat SEL TDI
Correction.
The voltage I am reading when the fuse is removed is on pin #3, one side of the contacts.

After testing my own installation, I determined that with the Jumper installed as I pictured above, I have 12v at the cig outlet. When I pull fuse 42, there is no voltage at the cig outlet. Therefore fuse 42 is the correct fuse for the circuit even with the relay removed, and a jumper installed.



Hope that helps.
 

nemesis500548

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Joined
May 4, 2008
Location
San Antonio, TX
TDI
02 Jetta
So I came across this thread looking for constant 12V power. But then I started thinking it would be nice to have the front plug still be switched to ignition for things like my radar detector and the rear plug constant for things like charging my phone while the car isn't on.

Of course both plugs are on the same circuit so I couldn't do this relay mod. So I just used a fuse tap to get constant power from fuse 31 and ran 1 hot wire back to the rear plug and cut and spliced it in. Easy enough since I already had all the trim apart to do my stereo upgrades and mission accomplished.
 

HowieE

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Dec 1, 2012
Location
Princeton NJ
TDI
2015 Passat stick shift
First run with the Passat in tow behind the Motor Home and a constant voltage from the cigarette light worked well.


Thanks for the info.
 

2015PassatTSI

New member
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Oct 13, 2020
Location
92405
TDI
2015
I did the wire with the 2 spade method on my 2015 Passat TSI SEL Premium. And it work was a 645 relay not 644 though
 

2015PassatTSI

New member
Joined
Oct 13, 2020
Location
92405
TDI
2015
Your jumper wire should be at least 12 gauge wire to match the fuse rating. Smaller wire can overheat, get hot and become a potential fire hazard due to current flow, depending what you got plugged in. This would be the case if an inverter were used or other high amp draw device. Most car electronics normally have a low amp draw.
I used 16 gauge is that a fire hazard?
I'm using it to power a small plug in Igloo Cooler
 
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