Ken51

I have a 2012 glk350 x204. I’m wiring up an aftermarket back up camera, but the front cigarette lighter is only putting out 8.6 volts. (Not enough to power the camera). Any ideas? The other option is to run a 12 volt wire from the battery. Where is the easiest place to get a wire from the battery thru the firewall?
Thanks for the help!

angryartichoke

Why don't you just pull the 12v signal from the backup lamp wire?

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Ken51

I may have to. I also need a 12 volt source for a radar detector, so that’s why I was trying to get a 12 volt source thru the firewall, then just use the 8.6 volts from the cig. Lighter as a signal wire in a relay. Thanks!

John CC

I have a volt meter plugged into my cigar lighter socket. 8.6 volts is not right!

habbyguy

Yeah, something is wrong with that circuit. I suspect that the fuse for the cigarette lighter plug is blown, and it's getting voltage backwards through some other related circuit.

FWIW, when I installed my rearview camera, I tapped into the power antenna / external amp circuit (thin blue wire coming from the top "big" plug, IIRC). I didn't worry about current drain since the camera draws almost nothing. This would be a good source for other lo-current accessories as well.

You can see the wire on my video just after the 10:00 mark...

Cosworth2000

Use the back light power to power the camera. You can also probe your fuse box to look for both power always and power ACC. Just never connect to any safety circuits to avoid problems. I installed a backup camera in my mother-in-laws B-Class with an Android head-unit and it made a big different. Also, if the radar has a cigarette lighter plug, you could just use that and purchase a dual port.