C-Class (W203) 2001-2007, C160, C180, C200, C220, C230, C240, C270, C280, C300, C320, C230K, C350, Coupe

Constant power in 12V cigarette lighter

Old Dec 28, 2010 | 04:34 AM
  #1  
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Constant power in 12V cigarette lighter

I couldn't find any threads that helped me in this matter,
If there is one please let me know.

My friend has an Audi A6 that has power in the cigarette lighter even if the car is turned off. But in my C203 -05 it cuts the power when the ignition is of as most cars.
Is there any way to bypass this wiring so it will always give me power even if the car is off?
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Old Dec 28, 2010 | 05:00 AM
  #2  
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From: Mississauga, Ont.
2007 C280 4matic Avantgarde
Only option is to find constant live wire and run it to cigarette lighter.
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Old Dec 28, 2010 | 05:31 AM
  #3  
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2002 s 500
how to do this
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Old Dec 28, 2010 | 05:41 AM
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Originally Posted by ontmiss
Only option is to find constant live wire and run it to cigarette lighter.
Yes, I would also want to know how to do this,
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Old Dec 28, 2010 | 08:08 AM
  #5  
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06 C230 SS 6spd
Originally Posted by robinbr84
Yes, I would also want to know how to do this,
I believe our radio has a 12v constant power source. You can probably tap into that or you can look under your dash by the fuses and test for a constant. You'll need a voltage reader and test each fuse to see if it gives a reading with the car off.
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Old Dec 28, 2010 | 09:05 AM
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From: Mississauga, Ont.
2007 C280 4matic Avantgarde
As phister says, and here is how to come to the wires. https://mbworld.org/forums/c-class-w...tructions.html
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Old Dec 28, 2010 | 09:36 AM
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Originally Posted by phister
I believe our radio has a 12v constant power source. You can probably tap into that or you can look under your dash by the fuses and test for a constant. You'll need a voltage reader and test each fuse to see if it gives a reading with the car off.
I read in another thread that the radio shuts down after 30 minuites if you leave it on. Do you know if this is correct? In that case it would be quite useless.
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Old Dec 28, 2010 | 09:37 AM
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Originally Posted by ontmiss
As phister says, and here is how to come to the wires. https://mbworld.org/forums/c-class-w...tructions.html
Do I need to go through all steps to find the wires I need?
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Old Dec 28, 2010 | 09:49 AM
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Originally Posted by robinbr84
I read in another thread that the radio shuts down after 30 minuites if you leave it on. Do you know if this is correct? In that case it would be quite useless.
Your radio does go off after 30 minutes but you can hit the radio power button and it turns back on. All radios have a constant 12v power source and an ignition source that powers the radio when the car is completely on. If you notice on aftermarket HU they have a constant power and an IGN power wire. Thats why radios have clocks and can save your settings cause it has a constant source. What you can do is have your car off and turn your radio on and after the radio goes off you can test the wire with the reader and see if its still giving off 12v reading.

You'll need to do all the steps in order to remove your radio to get to your wires.
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Old Dec 28, 2010 | 11:10 AM
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a C32 AMG & S-Works Tarmac
Originally Posted by robinbr84
I couldn't find any threads that helped me in this matter,
If there is one please let me know.

My friend has an Audi A6 that has power in the cigarette lighter even if the car is turned off. But in my C203 -05 it cuts the power when the ignition is of as most cars.
Is there any way to bypass this wiring so it will always give me power even if the car is off?
What is it you are really trying to accomplish? I needed a full time power source for my phone charger.

I went to Radio Shack and purchased a $5 cigarette adapter that has a base that can be screwed to another surface. I then opened the interior fuse door (located at the junction of the drivers door and the dash board), mounted the adapter just behind the fuses and just plugged the adapter wire into one of the open fuse slots.

It was only a bit more complicated than what I just typed here. It took about 10 minutes. The biggest time consumer was contorting my fingers to get the adapter behind the frame, then crimping a female wire clamp on to the wire. I then ran the charger wire along some dash seams, to the spot I like on my dash, to provide a very well concealed set up that provides constant power to the phone, key on or off.



Note that I plugged the adapter into a 20 amp fuse and put one leg of the fuse into the slot. (front yellow fuse)



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Old Dec 28, 2010 | 05:50 PM
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Originally Posted by ScottW911
What is it you are really trying to accomplish? I needed a full time power source for my phone charger.

I went to Radio Shack and purchased a $5 cigarette adapter that has a base that can be screwed to another surface. I then opened the interior fuse door (located at the junction of the drivers door and the dash board), mounted the adapter just behind the fuses and just plugged the adapter wire into one of the open fuse slots.

It was only a bit more complicated than what I just typed here. It took about 10 minutes. The biggest time consumer was contorting my fingers to get the adapter behind the frame, then crimping a female wire clamp on to the wire. I then ran the charger wire along some dash seams, to the spot I like on my dash, to provide a very well concealed set up that provides constant power to the phone, key on or off.
I have had a break-in in my garage (it's a garage for the whole apartment komplex) and I have a small 9 V camera I want to hide on the dashboard. So I need a power outlet even when the car is off. I liked your soulution alot but I did not quite understand if the 5 amp fuse was an already existing one in the sockets or if you used a new one. And did you just put it in a random slot or any one in particular? is there 12 V power in all slots?
Hope I didn't confuse you to much with my questions
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Old Dec 28, 2010 | 07:45 PM
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Originally Posted by robinbr84
I have had a break-in in my garage (it's a garage for the whole apartment komplex) and I have a small 9 V camera I want to hide on the dashboard. So I need a power outlet even when the car is off. I liked your soulution alot but I did not quite understand if the 5 amp fuse was an already existing one in the sockets or if you used a new one. And did you just put it in a random slot or any one in particular? is there 12 V power in all slots?
Hope I didn't confuse you to much with my questions
The fuse I used was inserted into a previously empty slot. We used a circuit tester to make sure it was a slot that had continuous power. If the tester lit with the key off, we used that slot. Several of the unused slots are continuously powered.

Oh, and I stand corrected. I used a 20 amp fuse.

You would be able to run a short cord to the camera from that fuse box. Otherwise, you would be running a cord all the way from the center console; pretty obvious set up with the cord.
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Old Dec 29, 2010 | 03:01 AM
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Originally Posted by ScottW911
The fuse I used was inserted into a previously empty slot. We used a circuit tester to make sure it was a slot that had continuous power. If the tester lit with the key off, we used that slot. Several of the unused slots are continuously powered.

Oh, and I stand corrected. I used a 20 amp fuse.

You would be able to run a short cord to the camera from that fuse box. Otherwise, you would be running a cord all the way from the center console; pretty obvious set up with the cord.
Ah okey, thanks very much for your help, this sounds like the esiest way at the moment. I will try it when I get home tonight!

I will post again when it's finished or if I need more help
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Old Dec 29, 2010 | 03:12 PM
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It all worked out! I used the way with the fuse box!
Thanks!
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Old Dec 29, 2010 | 07:51 PM
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Originally Posted by robinbr84
It all worked out! I used the way with the fuse box!
Thanks!
Glad it worked for you. I hope you catch the crook in the garage, before he breaks into your car, of course.
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Old Dec 30, 2010 | 05:01 AM
  #16  
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Originally Posted by ScottW911
Glad it worked for you. I hope you catch the crook in the garage, before he breaks into your car, of course.
Yeah, last time they smashed the windows of 5-6 volvos and stole the CD-disk changer that's located in the back on those models. Luckily they left my car alone so I thought a camera might make them leave my car alone in the future.
Happy new year to you all!
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Old Jun 1, 2016 | 01:42 PM
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Originally Posted by ScottW911
What is it you are really trying to accomplish? I needed a full time power source for my phone charger.

I went to Radio Shack and purchased a $5 cigarette adapter that has a base that can be screwed to another surface. I then opened the interior fuse door (located at the junction of the drivers door and the dash board), mounted the adapter just behind the fuses and just plugged the adapter wire into one of the open fuse slots.

It was only a bit more complicated than what I just typed here. It took about 10 minutes. The biggest time consumer was contorting my fingers to get the adapter behind the frame, then crimping a female wire clamp on to the wire. I then ran the charger wire along some dash seams, to the spot I like on my dash, to provide a very well concealed set up that provides constant power to the phone, key on or off.



Note that I plugged the adapter into a 20 amp fuse and put one leg of the fuse into the slot. (front yellow fuse)



Hi Scott;
Hate to resurrect an old thread, but the images no longer show here. Is it possible for you to post/send a link to the cigarette adapter that you placed behind the fuse box?
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