12V Socket Wiring: Pinout and Connections

Hi everyone,

Is there a standard for how a cigarette lighter socket should be wired (e.g., 'plus' on the inside, 'minus' on the outside)? How is it configured in the optional trunk socket available from Volkswagen? What is the wiring configuration for that?

Here's the translation:

'Background of my question: VW installed an outlet in my trunk for me: The wiring is as follows: 'minus' on the inside, and 'plus' on the outside. It's the opposite configuration for the cigarette lighter socket located in the front ashtray.'

Has anyone found a link to a standard sheet?

Regards,
Sure, here is the translation of the text from German to English:

'Micha'

Hello,

The wiring configuration follows the DIN ISO 4165 standard: positive terminal on the inside, negative terminal on the outside.
If there's a need, I can check the DIN standard sheet and create a PDF document.
According to this, the VAG dealer is obligated to pay damages if devices are damaged by being plugged in.



Best regards,
Marco Brinker.

The VAG workshop network has set a new record. My Golf doesn't have a power outlet in the back, but the cable is already there. Since the connector is polarity-protected (T-shaped), I'm wondering how someone could possibly connect it incorrectly.

New record for the VAG workshop network. My Golf doesn't have a socket in the back, but the cable is already there. Since the connector is polarity-protected (T-shaped), I wonder how someone could possibly connect it incorrectly.

Specialists always provide something particularly .

I also have a question about the power outlet: Can I connect my active subwoofer (150W max power, 70W nominal power) to it? The power outlet in my Golf is protected by a 20 Amp fuse. According to P = U * I (Power = Voltage x Current), that would be 12 volts * 20 amps = 240 watts. I was thinking of simply tapping into the existing wiring for the subwoofer's power supply. It would save a lot of work if I could just draw power from the outlet.


IDJK.

Hello IDJK,

It is possible. However, true enthusiasts might use a starter cable connected to the battery. Of course, it should have been stored for at least 2 years beforehand, oriented north-south, to allow for proper insulation formation .

The reversed polarity plug was definitely a special winter modification from the VAG workshop. Simple cooler boxes switch to heating mode when the polarity is reversed.

Best regards,
Christian.

chris11 wrote:

Hello IDJK, The reversed polarity plug was definitely a special winter version from the VAG workshop. Simple cooler boxes switch to heating mode when the polarity is reversed.

Now everything makes sense. I take it all back. VAG mechanics think ahead; at the next summer inspection, they'll just properly press that T-piece onto the canister .

Hello IDJK,
The reversed polarity plug was definitely a special winter version from the VAG workshop. Simple cooler boxes switch to heating mode when the polarity is reversed.

Now everything makes sense. I take it all back. VAG mechanics think ahead; at the next summer inspection, they'll just properly press that T-piece onto the canister .
That was good .

No, seriously.
I can confirm the statement made by Aliensafari.

The labeling is clearly defined according to DIN ISO 4165:

- Inner contact => Positive terminal.

- External contact => Negative (ground).

Most often, the specifications are also printed on the packaging of a 'supplemental' cigarette lighter socket.

The smallest problem you'll have is if the motor in your (simple) cooler box spins in the wrong direction.
You'll have a much bigger problem if you cause a short circuit.
where you compare the mass of your consumer to the mass of your car.

It's unbelievable how the Volkswagen workshops are competing with each other...

Did they at least ensure a backup power supply, or where are they getting the electricity from?
Don't tell me they tapped into the thin positive cable from the trunk light.

I also have a question about the power outlet: Can I connect my active subwoofer with a maximum power of 150W (nominal power of 70W) to it?

The performance values you list are likely 'musical power' and 'RMS power.' Therefore, they aren't directly related to the electrical power of your subwoofer. I would suggest running a separate cable (fused near the battery) in your place. While the outlet is protected by a 20A fuse, I don't believe the wiring is designed to handle that much current continuously. Also, the subwoofer will sound noticeably cleaner (bass cellar ).

@Jackrabbit82
The keyword is voltage drop.
With a wire that has relatively high resistance, you will experience a significant voltage drop (V = I * R).
This leads to a noticeable loss of performance and sound quality.
A voltage drop of 1 volt has a greater impact at 12 volts than it does at 230 volts, which explains why relatively thick cables are used for amplifiers.

I once connected the radio in my old car directly to the battery using 4mm² cables. It's hard to believe how much of a difference it makes!

Conclusion: Run the cables.

Can I simply run a single cable from the fuse box (positive terminal) to the subwoofer, then connect it to the chassis with a fuse in between?

Exactly. You can run the negative cable along the body of the car; that's how it's always done.

Edit:
You can either connect it directly to the battery, or you can find a free fuse in the central electrical system and connect it to the corresponding contact.

Hi,

Regarding the outlet: It's likely that the technician who did this probably installed an outlet (for 230 volts) at his home the night before and considered himself a great expert – "Polarity? What for... my outlet at home works just fine, after all..."

It's truly amazing what incredible achievements there are!

Best regards,

January.

Hi,

Thank you for the many responses.

@Aliensafari: I URGENTLY need the PDF document for DIN ISO 4165!


The long backstory (it's worth reading. It sounds pretty unbelievable. Nevertheless, I vouch for its accuracy!).

I ordered the Golf IV Variant from the factory with a 12V socket. Although the socket isn't actually installed, it is listed on the vehicle data plate and in the VAG system for my car (someone must have dozed off on the assembly line). I wanted the socket for my €400 super-trooper 4-port simultaneous fast charger (I'm a model airplane enthusiast. This allows me to conveniently recharge batteries when needed).

Then I had a problem with the car dealership: 'No, we won't install the outlet. VW doesn't pay us for that, and you surely don't think we would give you €300 by installing the outlet at our own expense.'
'So, I wrote a 'strongly worded' letter to the car dealership: The car was ordered with a power socket (as agreed in the contract), but it wasn't installed. They have until December 16, 2004, to retrofit the socket to fulfill the contractual delivery specifications. I personally delivered the letter and had them sign an identical copy with 'received on...' written on it. As soon as I drove off the lot, I received a call on my cell phone: 'Mr.... Of course, we will install the power socket. You will receive a free replacement car during the installation time. We will call you when the parts are ready!!!' Well then! It works! ('I also asked why they were initially unresponsive to my verbal inquiries, only to react positively after receiving a written letter. I received no answer.')

A workshop appointment has been scheduled and 2 hours have been allocated. Being as friendly as I am: 'I'll wait here so you don't incur unnecessary costs for the replacement car!!!'
So I was standing next to my car while the master technician and mechanic were discussing where the socket should go, because there's so little space on the right side. Suddenly, I said: 'You can definitely put the socket in on the left side; there's a bit more room there.' So the mechanic got to work, disconnected some wires, and pulled a cable towards the fuse box. The negative wire was connected to a grounding point at the back of the headlight.
Occasionally, another technician arrived with a piece of paper in hand, opened the hood, and looked around inside the engine compartment. When I asked him about it, he explained the issue regarding the recall due to the tandem pumps. For his colleague, who later disconnected the battery to install a socket, he left the hood open.
The flat-pin connectors were crimped with a water pump pliers . 'No, we don't have a crimping tool for that.' (It's so sad, considering how important polarity protection is for the connector).

Beim Wiederanbau der Blenden ein kleines Mallheur: An der Rücksitzbank die Verkleidung hielt einfach nichtmehr. Ich bemängelte das schon während dem Einbau. Also holte der Monteur einen von der Karosserieabteilung. Der nahm die Bende, knallte sie hin, haute mit der Faust zweimal drau und rief laut ' So! Jetzt! Jetzt sitzt sie richtig.' Ich erlaubte mir, leicht hinzufassen und schwupps war sie wieder lose. Also sagt ich: 'Die hält nicht.' Er richtig pampig 'Das ist schon richtig so' Ich: 'Nein, auf der anderen Seite hält sie.' Er recht laut: 'Dann klappen Sie mal die Rückbank rechts um, dann sehen Sie, dass die andere Blende auch nicht besser hält.' Ich klappte die Rückbank um, drückte heftig gegen die Belende und sagte: 'Also ich finde, sie hält.' Er:'Wenn Sie eine neue Blende wollen, müssen sie eine bezahlen.' Ich:'Ich hab' sie nicht kaputt gemacht. Ausserdem ist der Einbau der Dose ein Garantiefall! Ich bezahle nichts.' Er drohend:'Soll ich den Werkstattleiter holen?' Ich: 'Ja, gerne.' Werkstattleiter kommt und läßt sich kurz alles erklären und sagt: 'Wo ist das Problem? Wi'They are ordering a new bezel and will install it.' Me: 'Thank you.'
After the issue with the power outlet seemed to be resolved, it was time to address the insensitive interior sensors. The old ones were removed and replaced with new ones. The old ones were placed in the box of the new ones and, as instructed by the workshop manager, returned to the warehouse. Quote: 'We'll sell those again.'

The mechanic was re-learning the window controls and then wanted to close the hood. I stopped him: 'Don't you want to put the battery cover back on first?' He looked at me with a completely bewildered expression: 'I didn't take it off.'
The battery cover was gone! Just vanished! I started to get a little annoyed. Eventually, three people joined the search, which caught the attention of the workshop manager. I explained the situation to him, very politely (perhaps too politely). I even said, 'Maybe another employee took it to examine something.' (I didn't want to start with any accusations.) In the end, a battery cover was found in stock (it costs less than 7€, so it's really cheap), and I had it installed.
I was relieved that the four-hour nightmare was finally over.

However: I was very surprised by a battery cover that was hidden between two boxes and looked harmlessly on the workshop wall. If it hadn't had a piece of masking tape with a name on it that I didn't recognize, I would have probably mistaken it for mine. But they all look the same.

Perhaps you could help me with something else: I'd like to know what the VW workshop charges for this. Is there any way to find out that information? They didn't install the nicely labeled VW socket (like my friend has in his Highline), but a rather cheap-looking one instead. Somehow, I have a feeling that seeing the invoice won't make my frustration any less! (I hope you understand what I mean...)


Regards,
Sure, here is the translation of the text from German to English:

'Micha'

'@Wolfi: There's a ground point located near the taillights: Unscrew it, attach the ring terminal from the subwoofer, and screw it back on.'

Regards,
Sure, here is the translation of the text from German to English:

'Micha'

Hello,

If you go directly from the battery, you eliminate the voltage drop and potential interference of the central electrical system. But don't forget the fuse right after the battery, otherwise, in case of a short circuit, the cable might light up the entire car decoratively .

I can't understand how these amateur electricians could possibly connect the prepared connector incorrectly.

The reason the positive terminal is placed on the inner side is for safety reasons related to contact protection and short circuits. It's much easier for a conductive object to come into contact with the outer ring, which could potentially cause a short circuit, for example, if there's a charged item in the trunk. Some connectors even have the outer contact protruding slightly. Therefore, the "hot" terminal is preferably placed deep inside the casing. The ground connection can be exposed, while the positive terminal must always be insulated or protected.

Similarly, when it comes to lamp sockets at home, the same principle applies, but with the added benefit of personal safety.