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Hardwiring a Uniden R3 to the fuse box in the engine bay(help)
Hello everyone, proud owner of a w212 14 E63S. I recently purchased a Uniden R3 radar detector along with a hardwire kit off Amazon. I’m wondering if anyone has any experience or knowledge on where to hardwire the radar into the fuse box in the engine bay. I do see forums of people doing it to the mirror inside the car but I’m looking for a different route. Id like to tap into one of the fuses in the fuse box inside the engine bay. This radar says It requires 12v so I assume I’d need to find a 12v spot and just tap into that but I’m not sure. Also what kind of fuse tap id need to complete this task. Any information would help! Thank you Hardwire purchased from Amazon Uniden R3
One consideration - if you're set on using a fusebox, I'd look at tapping into the interior fuse box behind the drivers side dash, saves you the headache of figuring out where to run wires through the firewall, prying out plugs that keep engine noise out of the cabin etc.
They make 'fuse taps' that are just fuses that have an extra wire built in, saves from cutting wires so all you need to do is find a good ground spot to attach your ground wire to.
Make sure you test either with the radar or a multimeter and make sure whatever circuit you use shuts off in a relatively short time after turning off the car. Some of these stay charged and will drain your battery with the detector left on. That's why I like the mirror tap in mine as it's right there and shuts off within a minute or two after leaving (and you don't need to lock the car, which I never do in my garage).
One consideration - if you're set on using a fusebox, I'd look at tapping into the interior fuse box behind the drivers side dash, saves you the headache of figuring out where to run wires through the firewall, prying out plugs that keep engine noise out of the cabin etc.
They make 'fuse taps' that are just fuses that have an extra wire built in, saves from cutting wires so all you need to do is find a good ground spot to attach your ground wire to.
Make sure you test either with the radar or a multimeter and make sure whatever circuit you use shuts off in a relatively short time after turning off the car. Some of these stay charged and will drain your battery with the detector left on. That's why I like the mirror tap in mine as it's right there and shuts off within a minute or two after leaving (and you don't need to lock the car, which I never do in my garage).
Good luck!
hello, thank you for the information. So all I need to do is find the correct voltage/spot on the fuse box that’ll power on the radar as well as shut it off when the vehicle shuts off. Will that create a short of any sort or I’ll be fine tapping into any slot as long as it powers both the current fuse that was plugged in that slot & the radar. With the mirror tap did you have to splice any wires or was it just plug & play?
Our cars, like most German cars, can be sensitive to certain electronic things but no, you shouldn't cause any kind of short. Worst case is it may trip a fault code if some module gets upset at it's power being taken but then you just find another circuit. I've never heard of a small 12v accessory frying a control module.
I did tap wires on the mirror, I think I used those wire tap clamps you just press onto the wire to piggyback off of so it was really easy, but of course is not as easily removeable later on should you want to. I know people get worried about altering their factory wire harnesses, but honestly it's just some copper wiring, absolutely nothing that can't be repaired if you accidentally snip too much of it (also why I never tap super close to the end of a wire, leave enough room on both ends to splice later if needed). It's not fiberoptic cable, it's not carrying voltage to a fuel injector that if it had an issue could melt a piston etc.
Looking at a diagram online for the interior fuse box, I think the first one I would try is the 'overhead control panel unit'/pano roof control. I know the roof controls don't work without the key/car on position 1 or 2, this module could still be powered up for a time after the door is opened etc but hopefully that is one that powers down after a minute or two. It's probably the same one I tapped in the mirror. Get one of those fuse things (I think they are minis in the interior box?) and you can just spend a few minutes testing them. Once you have a winner, then it's just the job of running and hiding wires so should be pretty easy.
Our cars, like most German cars, can be sensitive to certain electronic things but no, you shouldn't cause any kind of short. Worst case is it may trip a fault code if some module gets upset at it's power being taken but then you just find another circuit. I've never heard of a small 12v accessory frying a control module.
I did tap wires on the mirror, I think I used those wire tap clamps you just press onto the wire to piggyback off of so it was really easy, but of course is not as easily removeable later on should you want to. I know people get worried about altering their factory wire harnesses, but honestly it's just some copper wiring, absolutely nothing that can't be repaired if you accidentally snip too much of it (also why I never tap super close to the end of a wire, leave enough room on both ends to splice later if needed). It's not fiberoptic cable, it's not carrying voltage to a fuel injector that if it had an issue could melt a piston etc.
Looking at a diagram online for the interior fuse box, I think the first one I would try is the 'overhead control panel unit'/pano roof control. I know the roof controls don't work without the key/car on position 1 or 2, this module could still be powered up for a time after the door is opened etc but hopefully that is one that powers down after a minute or two. It's probably the same one I tapped in the mirror. Get one of those fuse things (I think they are minis in the interior box?) and you can just spend a few minutes testing them. Once you have a winner, then it's just the job of running and hiding wires so should be pretty easy.
Yessir, sounds like a plan. I do think ‘overhead control panel/pano’ could be a possible contender. We won’t know till I try so I will put that on the list! I do need to shop around for minis/fuse taps. I would assume I probably need to know what slot I’m using before purchasing one of those?
As an alternative to the mirror wires, I hardwired my Valentine into the 12V center console cigarette lighter outlet. It's only powered when the car is on and if the fuse blows it only affects the cigarette lighter. Have had no problems since install.
As an alternative to the mirror wires, I hardwired my Valentine into the 12V center console cigarette lighter outlet. It's only powered when the car is on and if the fuse blows it only affects the cigarette lighter. Have had no problems since install.
It's pretty straight forward. Just have to remove some trim and the shifter assembly to get to the cigarette lighter plug wires. It's a few screws and just carefully prying off pieces that are clipped in, especially the trim piece that has the mode selector wheel/suspension/AMG buttons on it. It's easy to rip off the connecting wires if you're too aggressive. Probably took an hour or so to do it, including time spent soldering the leads in. Here's a video showing it.
It's pretty straight forward. Just have to remove some trim and the shifter assembly to get to the cigarette lighter plug wires. It's a few screws and just carefully prying off pieces that are clipped in, especially the trim piece that has the mode selector wheel/suspension/AMG buttons on it. It's easy to rip off the connecting wires if you're too aggressive. Probably took an hour or so to do it, including time spent soldering the leads in. Here's a video showing it. shifter removal and cigarette plug exposure.
sweet! Thanks for the video, I’ll for sure look into this route if there isn’t another way
OP: Like others here, I used the overhead console for the power to the radar detector. Easy and does turn off with the ignition.
If you remains focused on the getting power from the fusebox in the engine compartment, there is an "easy" way to get through it since our cars were prepared to have a clutch pedal. See my writeup for the installation of a laser jammer for more details: ALP install in my 2016
Anyone know if it’s possible to tap it into the fuse box in the truck. I’m going to attempt to tap it into the cigarette lighter fuse but I’m not sure if it’ll turn on/off with the vehicle or just stay on. I believe it’s fuse 71 in the trunk
Anyone know if it’s possible to tap it into the fuse box in the truck. I’m going to attempt to tap it into the cigarette lighter fuse but I’m not sure if it’ll turn on/off with the vehicle or just stay on. I believe it’s fuse 71 in the trunk
This is how I wired my dashcam, the cigarette lighter switch is the one to use. It will turn on and off with the vehicle.
Get a fuse splitter; they are pretty inexpensive:
This is how I wired my dashcam, the cigarette lighter switch is the one to use. It will turn on and off with the vehicle.
Get a fuse splitter; they are pretty inexpensive: https://www.amazon.com/JABINCO-Circu...e%2C144&sr=1-5
does it turn on and off with the vehicle or does it stay on? I believe outlet 71 is the cigarette lighter and that’s the one I’m going to be going through. Im just hoping it’ll power off and on with the vehicle
This is how I wired my dashcam, the cigarette lighter switch is the one to use. It will turn on and off with the vehicle.
Get a fuse splitter; they are pretty inexpensive: https://www.amazon.com/JABINCO-Circu...e%2C144&sr=1-5
Here's how I wired up my 2 dash cams (front/rear) to the fuse box in the trunk. I used the fuse splitters, no problems so far.
I can confirm that the fuse for 72 and 38 (the two slots I used) turn off when the car is off, as well as the fuse for 71 (which I used to power my Valentine).
Here's how I wired up my 2 dash cams (front/rear) to the fuse box in the trunk. I used the fuse splitters, no problems so far.
I can confirm that the fuse for 72 and 38 (the two slots I used) turn off when the car is off, as well as the fuse for 71 (which I used to power my Valentine).
very well needed information thank you! The fuse tap in the yellow brick I assume is what you used for the valentine radar correct? Here is the fuse tap I bought. Let me know if this is the correct one! Thank you again
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