GLK3502k

Attempting to install a dashcam and was wondering if i can cut a USB cable and connect it to the rain sensor plug to draw power? If so, which cable should connect to where? Can i safely draw power from the rain sensor (please see pics below)
Thanks!
https://ibb.co/ifz84v
https://ibb.co/bDdPcF

If that can't be done, I'll have to run the USB cable all the way to the cigarette lighter which won't be really practical.

Funkwagen

Do you have a 12v outlet in the glove box? It'd be easier to run a cable along the roof and down the A-pillar into the glove box. If you do I can take a picture of my setup for the basic idea.

I thought about doing something similar to what you're thinking but I remember deciding there were no "good" sources of 12v power available around that area

edgalang

That's exactly what I did the 1st time. Worked flawlessly....UNTIL I had my windshield replaced, and the installer (trying to be nice) attempted to reinstall the wire and blew a fuse, causing the AC to go bonkers. After getting it repaired (found blown fuse) I tapped into the overhead console instead (more room to work, plus I was a little gun shy touching the rain sensor again).

GLK3502k

Good to know thanks , so which wire should connect to where based on the pic? My guess will be the red from the USB to the red from the rain absorption and the black from the USB to the brown from the sensor, is that correct?

GLK3502k

i don't remember seeing a 12v outlet in the glove box, mine is the base model. On a separate note, i was frankly disappointed and surprised to find out for example that i don't even have courtesy lights on the doors which to me is more about safety than anything else! Never heard of a car in 2014 that didn't have that nonetheless a MBZ...wonder now what else they cut corners on...sorry for going on a tangent here.

GLK3502k

I don't have a 12v outlet in the glove box so was wondering which wires i should connect to from the rain sensor or would it be easier/faster to use a connection from the dome light?

bop11

If you use any of the systems up in the top of the windshield , you run the risk of blowing an output transistor in the processor. Even the lights are controlled through outputs in the processor not by switches to ground as in the old car systems. This means that the switches are very low power processor inputs so the wires can be small. You must have a cigarette lighter somewhere up front. Run the power from there.

GLK3502k

Thank you for the info, I was also considering using the USB port in the middle console but couldn't find an easy way to run a wire inside that console. There is what looks like an empty switch next to the USB port but I couldn't remove/open the cover. How difficult it is to remove that entire middle section so that i can drill a hole in cleanly?