Larrold

I have a 2018 C300 cabriolet. I want to hard wire a dash cam to power going to the rear view mirror. I have read a lot of instal threads about tapping in to the fuse box or going down to the lighter. I want to use a mirror tap kit with a mini usb and just pop off the rear view mirror cover and tap into some power there by slipping the taps into a 12v plug and the ground. I don't know what power is running to the mirror. I read some threads that say it is the rain sensor power. I thought that there might be some power to the dimming mirror and or garage openers. I saw a video with the cover off and it looks like there are two plugs with a blue wire that might work. I would appreciate any info on what is behind the mirror and what wire to connect to safely. It is a lease car and I don't want to cut into any wires or remove any panels. I will be turning the car in about 20 months. The mirror tap seems to be the easiest way to connect.

MBpippo

Hi Larrold. You have posted in the incorrect forum. Try the C205 forum where you might find someone that’s done this already. Good luck!

Larrold

Hi MBpippo,

Thanks for your reply. I did check out that forum but noticed that it doesn't get many views or replies. I was hoping that maybe the mirror wiring was pretty much the same and someone might see my post here. At first I didn't know the difference between the C204 and C205 numbers and still don't know where they come from. I just would refer to the car as a C300 Cabriolet. Prior to this car I belonged to the SLK forum and never noticed a reference to that car as other than an SLK and the model number. I will repost this in the other forum also.

Take care

MBpippo

No worries Larrold. C205 is the current model and C204 the previous model. Is the mirror setup different in the cab compared to the coupe or sedan? I’m thinking the sedan forum would be the most active. You could also try https://forums.mbclub.co.uk/ which is another active MB forum. All the best.

Larrold

MBpippo, I am not sure what the difference is in the coupe or sedan. I just had my car in for service and had a sedan loaner and didn't even think to look at it. I have seen several pictures of either the mirror or light panel below the mirror on several sites and they all seem different. It seems the convertible has the easiest cover to remove by just using a trim tool and popping it off. My main concern is what wire to connect to when I take it off. I read where there is a red and brown wire that is for the rain sensor that turns off when the car is off which is what I want. The red is hot and the brown is ground. I just want to make sure that what I am tapping into won't cause any other electrical problems. I was just hoping someone who knows the wiring behind the mirror could give me some advice. I am going to pop off the cover during the week and see what is up there and put a voltage meter on the wires to see what I get. I am just surprised that so many run the wire under the headliner and down the door to the fuse box when the mirror is right there. You can buy the mirror tap for about $25.00 and don't even have to splice or sodder any wires. Maybe the availability of the wire taps is not well known. I only know about them because my son in law uses them on all his BMW's for his radar detector. If, I am successful with the installation I'll post it here.

openwheelracing

Hmm, my radar housing is much smaller....