[crosis]

I want to hard-wire install a dash cam into my 2011 BMW X3. I have all the appropriate parts. What I'm unable to discover are which fuse slots to use for the ACC and Constant.

For the life of me i cant make sense of the BMW fuse diagram nor am i able to accurately test which fuse slot is appropriate. I've provided images of the Fuse Tap, the glove box fuse bank and the vehicle's fuse diagrams. Please, someone just tell me which fuse numbers will suffice for ACC and Constant. Keep in mind the Fuse Tap must be installed into a suitable slot which accommodates the adjacent tail / power side.

Thanks

[richardodn]

First of all, I've not done this myself. Be sure to verify, anything I suggest. Second, I assume you have a device that will cut power to the circuit if the battery drops too low.

For constant power, picking the right fuse locations is pretty straightforward. Fuses 14, 15, & 56, among many others, are all hot at all times. They are all part of the anti-theft and central locking circuit. (Door with key icon.) Of those, I'd go with 56 as it only powers the alarm siren. In the event you screw something up, it would only bring something non-critical down.

Accessory power is a bit different. Unlike older cars, there is no simple switch controlling that. Instead, there are various power levels controlled by the Car Access System (CAS) module. I found this post explaining the various power terminals available in modern BMWs. I can't direct link it, but search google for "bmw-battery-terminals-explanation-15-15n-15wup-30-30g-30g_f-30b-30f-50.5630"

I've reproduced part of the post here.

Terminal 0 - Terminal 0 is a logical terminal and does not provide a power supply. Terminal 0 comprises Terminal 30, Terminal 30B and Terminal 30F.
Terminal 15 - Terminal 15 is used to signal the status “Ignition ON/Ignition OFF” rather than as a power supply. That applies, for instance, in the case of the digital motor electronics (DME), the footwell module (FRM) and BMW Night Vision.
Terminal 15N - Terminal 15 N (Overrun) is used for control units and electrical loads operating at status “Ignition ON” when the vehicle is being driven. That applies, for instance, to the lane departure warning (SWW), short range radar (SRR) and Night Vision.
Terminal 15WUP - Terminal 15 Wake-up is used to wake up control units that can not be woken up by bus communication.
Terminal 30 Control units and components that must continue to function up to the point when the battery is completely discharged are connected directly to the continuous positive, Terminal 30. That relates to units such as the Car Access System 4, roof function center and the junction box module.
Terminal 30B (Terminal 30g) - Terminal 30 Basic is used for control units and electrical loads operating when the driver is present. That applies primarily to components such as the seat module, digital motor electronics (DME), gearbox control unit (EGS), Controller and CD changer.
Terminal 30F (Terminal 30g_f) - Terminal 30 Fault is used for control units operating in the driver’s absence. That applies, for instance, to the trailer module (AHM), footwell module (FRM), instrument cluster and automatic climate control module (IHKA).
Terminal 50 - Terminal 50 is provided for controlling the starter motor.
Terminal R

Ideally, it looks like you probably want terminal 15. However there's really no easy way to pick that up. It's used internally and directly wired to the modules that consume it. Your next best bet is terminal 30B. There are loads of fuses powered by 30B. A convenient one is fuse 67 which powers some seat adjustments.

These are both mini fuses so make sure you are using the mini taps. Also remember that both the fuse block and the tap have a hot side and a fused side. Be sure to match them correctly.

[crosis]

Thank you very much, richardodn. Quality answer!

[Dekero]

Umm order the OBDii power tie in for it.. I have it in my X5 and my 22 Tucson... Works amazingly and has a safety shut off valve if voltage dips.

Easy install...

[tracer bullet]

I'll just add that if you think a particular fuse is live or not may be a dynamic situation. Back in the 80's you got what you got and could rely on it. Today everything is run through various PCM's and something that is off might come on 5 minutes later, and something that is on may turn off 5 minutes later. 5 minutes of course not being an exact time, just saying that before you feel sure you've got the right one be sure to take a full drive to check it out, as well as park, lock the doors, and etc. to go through all the motions.

[pokerface]

I went through this awhile back.

I went with fuses 58 and 65

https://x3.xbimmers.com/forums/showt...hlight=dashcam

[mikekay]

+1 for fuse 58 I always thought it was home link, but it seems its the COMBOX fuse? Anyone worked perfect right until I sold it. Good ol' mobius actioncam with super capacitor... Good luck man!

[rayen]

I connected my dash cam right from connector from rain sensor and mirror dimming - you have gnd, 12v allways on and 12v only when engine running
just check with voltmeter, i dont recomend to connect to 12v that is allways on, my camera has battery so it will autoshutdown 30 seconds after car stoped
my cammera drains 50mA, so it will not overload any fuse that are these connected to