Alfa Romeo Stelvio Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Hello all,

I'm trying to hardwire a Blackvue B-124x battery to my rear fuse box so I can stash it under the floor. I've seen people wire to the front fuse box which is easier, but I don't want to place the battery in the glove box or under a chair. I was going to use the F22 fuse which protects the 12v power socket. Is this advisable? Also, which screw would be the best for my ground wire in this scenario? I'm new to this stuff and it's just a little difficult to find information on all of this, but I'm trying. Thanks!

21108
Trunk fuse box diagram: Alfa Romeo Stelvio (2017, 2018, 2019..)
 

·
Registered
2018 Stelvio Q4 Sport, MonteCarlo Blue
Joined
·
77 Posts
I assume you did this by now. But in case it helps anyone else in the future:

In general, yes, that is fine. Did you tap onto the wire or did you do the add-a-fuse option? I would have suggested the piggyback fuse option to leave the OEM wiring alone and direct-wire your new device to it's own fused pigtail.

Any metal location that is welded to the car body or frame can be used as a ground, but it works best if it is an un-painted surface. For example, if you put it between the grey plastic of the fuse assembly tab at the bottom there and that metal mounting tab, I would have scuffed the red paint off (under the grey tab) for a better connection.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 ·
Thanks for the response! Unfortunately I ran into a different problem. I tried to use a piggyback fuse but it didn't fit i the proper orientation. The bottom of the fuse f22 is the load side, this would leave the fuses sticking out the right of the piggyback and not being able to go in all the way in. I've read piggybacks in the wrong orientation can cause additional load on the car fuse so I haven't found a nice solution yet.
 

·
Registered
2018 Stelvio Q4 Sport, MonteCarlo Blue
Joined
·
77 Posts
I'm not sure if you have the Subwoofer or whatever in there, but there has to be some spare room on the Driver's side, and your battery comes with a "cigarette plug" adapter, and there's already a 12v power outlet in the trunk back there...a quick solution for now would be to just mount your battery on that side and plug it in (instead of hard-wire it in). But likely that's probably close to what you are doing now, because you said 'a clean solution' :)

F22 is specifically for "12V socket in luggage compartment", so not the one in the dash. Just the rear one. If you have nothing in the 12V power outlet, there is zero load, let alone more. But that said, a piggyback in the wrong orientation is unwise for several reasons, so lets leave it at: Good job not wiring it in incorrectly.

The way a piggyback works when installed correctly is the original component is still protected by its factory fuse, and the pigtail is protected by whatever fuse you put in there. You want to be a little careful and make sure the bus you are tapping is capable of providing the additional power. But the source does not have to be the 12V power socket fuse. For the fuses near location F84, it appears that the feed side is the top and the body side is the bottom. There is both a 20A and 30A fuse on that bus, plus space for an additional whatever option that F84 was designed to cover from the factory (probably something on a higher-feature model). So it would be safe to tap one of those fuses for what you are doing, having the pigtail pointed down towards that conveniently unused cavity. Now, that said, that bus could be 12V all the time, or it could use a relay, so you might want to test one of those fuses to make sure it is powered on all the time. If it is relay-controlled it might not like the additional power draw from that bus. If it is 12V all the time, you are 100% good to go. I'd suggest tapping the one that has the same rating as the fuse you intend to use...and you have 10/20/30 to choose from.


21292
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #5 ·
Brilliant explanation! My final concern, if the fuse is powered all the time, wouldn't it be bad to tap as it may drain my battery? This is why I initially went for the F22 fuse, as it was on with ignition. Thank you kindly for the explanation. I feel like you're putting together the puzzle pieces of information I managed to gather but not put in place yet.
 

·
Registered
2018 Stelvio Q4 Sport, MonteCarlo Blue
Joined
·
77 Posts
Absolutely valid concern. Your Blackvue battery should draw the most amount of power when it is low-to-dead, and only trickle charge when it is full. This means after you drive around it will draw very little, but if you leave it parked in your garage for a few days, it will draw more from your car battery and could result in a dead car battery. (Your car battery does not need to be 0V in order to be unable to start the car. Usually voltages around the 9's or lower means you cannot start your car)

I read the PDF for install, and they absolutely recommend a switched lead for this. I was just issuing a bit of caution to make sure the vehicle bus and relays can handle that extra load the add-a-fuse will throw at it, rather than say "Any will work". IE> If you are tripping protection relays, try a different fuse. "Any will work" generally on a constant 12V bus though. Sorry if I was unclear. So yes, in your case, do go hunting for a switched 12V source. the other thing you COULD do, if you had two add-a-fuse units, is use one on the F84 fuses for the source, and add the other one on F22 (yes, in the wrong direction) only as a trigger for a 12V relay. That way, the relay trigger is drawing only Milli-amps from the power outlet fuse, but using the actual current from your properly protected fuse location to charge the BlackVue battery pack. It's more complicated this way, but saves you minor hassle of finding an otherwise ignition-sourced fuse in the right direction with enough room for the pigtail.

In this case, if you choose this route, buy a simple 4 pin 12V relay.
Pin 86 comes from the F22 fuse pigtail
Pin 30 comes from the "F84-area" pigtail (properly fused in the right direction)
Pin 87 goes to the BlackVue battery pack
Pin 85 can go to the same ground spot the BlackVue battery is using.

21308
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #7 ·
While it may seem a little more complicated, I think this could be the solution I'm looking for. My main concern was keeping everything in the trunk space for the wiring and this allows me to do that. Even with the relay, everything is still tucked in basically the same place. I appreciate the in-depth explanations, they really helped me out here!
 

·
Registered
2018 Stelvio Q4 Sport, MonteCarlo Blue
Joined
·
77 Posts
While it may seem a little more complicated, I think this could be the solution I'm looking for. My main concern was keeping everything in the trunk space for the wiring and this allows me to do that. Even with the relay, everything is still tucked in basically the same place. I appreciate the in-depth explanations, they really helped me out here!
You're welcome! Happy to help, and good luck modding. If you have any questions, feel free to PM me or update this thread and I'll keep an eye out.

And as a note: Because you are installing the add-a-fuse in F22 "backwards", make sure to use the same value fuse in that location as stock (20A if memory serves). The relay itself will draw very little, but because that 12V power outlet will have two fuses in parallel, it will blow the lower value fuse if you plugged in a higher current device.
 
1 - 8 of 8 Posts
Top