Blown fuse?

 

They for sure blow a fuse. How’s the fit cam install go? You tap in for power ? They could’ve easily shorted a circuit which would’ve blown a fuse.

I believe someone published the detailed drawing that shows the fuses if not I wonder if an OBD2 reader would mention exactly which fuse.

 

Thanks, I’ll check that. Hopefully it’s that simple! I’m technically inclined, but have never done this before 😅

the installation itself was mostly straightforward - I had to tap in for power, indeed. But putting the housing back together proved incredibly challenging. I’m 2 hours in and it hasn’t gone together correctly yet. The original housing goes back together within seconds (I’ve done it multiple times now).

 

This might be an ignorant question, but why not just use the built-in Drive Recorder?

 

Based on posts here on the forum, the built in Drive Recorder is terrible and unreliable.

 

Fuse looks good to my novice eyes. I’ve booked it in at my BMW Service Centre on Thursday for them to fix it.

 

If you have access to a multimeter put the fuse back and test any fuse relating to the light or acc… you can download the fuse card for your car using your vin.

But almost certainly a blown fuse…. Dont mention to bmw what you were doing first!!

 

I’ve been meaning to get a multimeter anyway, so this is a good excuse. It arrives tomorrow. Will post here again with an update when I have one. Thanks everyone for the advice so far.

 

Try opening back up the mirror clamshell and reseating the connection?
I installed a similar device (fitdvr) few weeks ago, and it needed a firm click to get the connection into the the fitdvr and then into the car.

 

That’s a good shout too. I’ll give that a try tomorrow - it should be super quick to try. I’ve got the knack of taking the plastic coverings off and on pretty quickly now.

 

Maybe do a step-by-step with pictures so others can learn to do this? My husband would string me up if I started blindly taking the 2025 car apart already. But, if there was a guide I could follow…

 

This one was the one i used when doing mine

https://www.i4talk.com/threads/nextbase-dashcam-clean-install.5002/?post_id=91343#post-91343

Mirror tap part https://www.i4talk.com/threads/crea...reads/created-a-tutorial-video-for-mirror-tap-for-radar-detector-dash-cam.3979/

 

This was the one from FitcamX that they suggested for the i4. It does look very easy, but I guess I’m a case study of what happens when it goes wrong.

 

This morning I also found that the motor on the boot (trunk) doesn’t work either. Pressing the button unlocks it, but it has to be manually lifted and pushed down. I’ve no idea how a simple dashcam install could turn into something so massive. Dreading what else I’ll find.

I ran it through ChatGPT, just out of curiosity, and it suggested fuses too, but also recommended disconnecting the 12V battery for a period to allow the system to reset. I haven’t done that though.

Multimeter has arrived, but need to wait for it to stop raining before I can get in there.

 

I ran it through ChatGPT, just out of curiosity, and it suggested fuses too, but also recommended disconnecting the 12V battery for a period to allow the system to reset. I haven’t done that though.

Here's the proper 12V disconnect procedure, you'll notice it includes a fairly lengthy procedure that requires HV disconnect also:

https://www.i4talk.com/threads/safely-disconnecting-and-reconnecting-the-high-voltage-system-including-12v-a-step-by-step-guide.13751/

I don't think you need to disconnect the 12V battery here though.

 

It was indeed a blown fuse. They weren’t specific about which one, just for “the main body control unit”. Cost was £150, and no mention of it affecting the warranty.

Now the question is what could I have done to cause it? What should I avoid doing if I attempt this again? (Perhaps I’m better off calling in an expert - even without this distraction, I had a lot of trouble actually getting the enclosure fitted correctly)

 

Now the question is what could I have done to cause it

You likely shorted a circuit by briefly touching the taps together. You can do one tap at a time to avoid this, make sure each tap is secured and can’t slip out before you plug the other tap.

 

It’s always safer to disconnect power when playing with wiring. Even a momentary misconnection, or unintended live to ground is enough to blow a fuse (it’s what they are there for after all). The Body Domain Controller looks after a lot of different functions leading to lots of them disappearing if its power gets chopped by a fuse.