Continuous 12 Volt Power Source ?
Thread Starter
MBWorld Fanatic!
Joined: Aug 2002
Posts: 1,308
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From: Atlanta, GA USA
2000 MB G500 NMLE, 2015 Audi Q7 3.0 TDI Prestige
Continuous 12 Volt Power Source ?
Are any of the 12 volt power sockets continuously on independent of the ignition? In my Q7 they were always on. It doesn't look to be the case with this ML.
We're planning a cross country trip with a 12 volt Engel fridge; and there will be times where the car is parked and turned off. I would like to be able to continue to supply power to the Engel when parked.
Is there any way to activate this using the STAR diagnosis computer?
Please advise. TIA!
We're planning a cross country trip with a 12 volt Engel fridge; and there will be times where the car is parked and turned off. I would like to be able to continue to supply power to the Engel when parked.
Is there any way to activate this using the STAR diagnosis computer?
Please advise. TIA!
Member
Joined: Oct 2013
Posts: 224
Likes: 28
From: Western Europe
2017 GLS 350d
Im not sure this can be done, but I would rather pull a wire from the 12V battery input below the rear passenger seat straight to the 12v outlet in the cargo, and just add a switch and a fuse on that additional line. You just need to make sure this is a double switch that will open the live wire from the original wire when it closes the newly added one, so that the fuses values dont add up.
Overall that shouldnt be too difficult to implement.
Overall that shouldnt be too difficult to implement.
Thread Starter
MBWorld Fanatic!
Joined: Aug 2002
Posts: 1,308
Likes: 35
From: Atlanta, GA USA
2000 MB G500 NMLE, 2015 Audi Q7 3.0 TDI Prestige
Im not sure this can be done, but I would rather pull a wire from the 12V battery input below the rear passenger seat straight to the 12v outlet in the cargo, and just add a switch and a fuse on that additional line. You just need to make sure this is a double switch that will open the live wire from the original wire when it closes the newly added one, so that the fuses values dont add up.
Overall that shouldnt be too difficult to implement.
Overall that shouldnt be too difficult to implement.
The other option is to tap the two poles located under the hood which are used to recharge or jump start the battery. They're very accessible and would only need to be used when the car is parked.
It's really a shame that MB makes this so hard! The much better way would be to do as is done on the Audi Q7. The 12 volt sockets are always hot, but have a sensor that disconnects them if the battery approaches too low to start the car. Good engineering sense seems to be beyond MB's ability sometimes.
Last edited by DUTCH; Jul 3, 2014 at 09:53 AM.
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Joined: Aug 2013
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From: Alberta, Canada
'18 GLE63S AMG /'19 PORSCHE TURBO S / '09 CORVETTE ZR1 /'14 LEXUS RX350/'16 RAV4 Ltd
Actually you can disconnect main battery without losing any programming..there is a supplemental battery that maintains all settings..
Thread Starter
MBWorld Fanatic!
Joined: Aug 2002
Posts: 1,308
Likes: 35
From: Atlanta, GA USA
2000 MB G500 NMLE, 2015 Audi Q7 3.0 TDI Prestige
Thread Starter
MBWorld Fanatic!
Joined: Aug 2002
Posts: 1,308
Likes: 35
From: Atlanta, GA USA
2000 MB G500 NMLE, 2015 Audi Q7 3.0 TDI Prestige
Best solution is to power off the trailer hitch electrical plug. There is always on +12 volts and a ground in there.
I took a 7-pin plug and wired a female cigarette socket to it. When parked, I'll disconnect the trailer, plug in the 7-pin cigarette socket adapter, plug in the Engel and all is good.
I took a 7-pin plug and wired a female cigarette socket to it. When parked, I'll disconnect the trailer, plug in the 7-pin cigarette socket adapter, plug in the Engel and all is good.
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MBWorld Fanatic!
Joined: Aug 2013
Posts: 1,267
Likes: 56
From: Alberta, Canada
'18 GLE63S AMG /'19 PORSCHE TURBO S / '09 CORVETTE ZR1 /'14 LEXUS RX350/'16 RAV4 Ltd
I disconnected my battery when I sent the ECM in to Renntech and no reprogramming was needed when I reconnected..In my vehicle I'm certain there is a backup
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