[red-max]

Hello,

I'm planning to install my TomTom in my new (to me) 2009 E92, and would like some advice on where best in the cabin to pick up the 12v feed for hte charger.

In my previous car, I had a Nokia bluetooth kit professionally installed, so I just tapped into the fused 12v feed provided to that, which was in the panel under the glovebox lid. This car has built-in bluetooth, so just the TomTom to wire in.

I was thinking that I could perhaps pick up 12v feed from under the cigar lighter, but I'm not sure how easy is is to remove the centre console...

Thanks,

[Sh0cker]

For my radar detector I used a piggyback tap (not sure what the word is...it's a thing that fits over the fuse blade and you fit it back in the fuse panel) for the homelink fuse. So it comes on when the ignition it "on" but not "accessory". Make sure you tap the fused side so it will be protected.

The wire runs up the A pillar under the trim and across under the headliner. If you mount your Tom Tom low you could run the wire across the bottom of the windshield out of sight.

[red-max]

Originally Posted by User Name

For my radar detector I used a piggyback tap (not sure what the word is...it's a thing that fits over the fuse blade and you fit it back in the fuse panel) for the homelink fuse. So it comes on when the ignition it "on" but not "accessory". Make sure you tap the fused side so it will be protected.

The wire runs up the A pillar under the trim and across under the headliner. If you mount your Tom Tom low you could run the wire across the bottom of the windshield out of sight.

Thanks, I didn't know these were available, though I can't seem to find anywhere in the UK to get them. I did find a number of US suppliers on eBay, perhaps I'm searching for the American name, "fuse tap" - anyone know what they're called in the UK?

Also, how do I know which fuse to tap into?

Thanks,

[Sh0cker]

You can also use vampire taps on one of the wires under the sunroof control panel but I didn't like that route for my own car.

As a last resort, I have actually been able to successfully solder a wire onto the metal tip that is visible on the top of the fuse. Be careful not to melt too much plastic if you try this.

There's a diagram of fuse numbers in your fuse box. Find the one for your homelink, maybe 18?



(That picture was stolen from HERE)

[red-max]

Thanks very much for your help so far. I've ordered some "ADD-ON" ATC AUTOMOTIVE FUSE TAPs from the US (eBay), not sure exactly which of the 3 sizes they're going to be. Meanwhile I'm tempted to solder onto a fuse blade to make my own "tap".

I had a search around, and took a look in the fusebox, and I have a few more questions:

1/ Is there a decoder for the little pictograms? Is Homelink the one I have circled in Orange? Strangely, I have two 5A fuses in 07 and 63 (do UK cars have Homelink?) - I guess I could piggyback on one of these...

2/ I have empty slots in positions 31 and 32, but I'm not sure what the symbol represents, a towbar perhaps? Circled in Lime green.

3/ I have an empty slot in 42, which seems to be for the radio (circled in Blue), at least I think it's a radio... might give that a go.

[red-max]

Update: I managed to complete the TomTom installation today.

I modified a couple of spare fuses, by breaking the filament with a craft knife, and soldering a piece of wire to the top of one of the metal blades, then with a DVM I measured the voltage on a fair number of unused fuse slots with the ignition off and on. I was surprised that most of the empty fuse slots had 12V on them, even with the ignition key out, but finally I found that fuse 9 on my car (looks like a door mirror on the crib sheet) which only had power with the ignition on, which is what I wanted. So I connected into there for 12V, and I drilled into the metal bracket (v.similar to the picture in post number 4) to get a good ground, and it all works, so I'm very pleased.

Thanks to User Name for helpful information and pointers to the US Valentine hardwire threads.

[USAman]

Do you have any pictures of your modified fuse you created? Would be very interested to see this, as it seems a cracking option to install something like a tomtom.

Cheers,

[red-max]

Originally Posted by ric

Do you have any pictures of your modified fuse you created? Would be very interested to see this, as it seems a cracking option to install something like a tomtom.
Cheers,

Hi Ric,

I modified two fuses, on was a blade fuse, the other a mini blade fuse. The mini blade was the one I actually fitted to the car in position 9 of my fuse box. The one I have left is bigger, but I've taken a picture of it to give you some idea, with a non-modified mini blade fuse next to it. All I did was use a craft knife to remove the fuse filament, then I cut away a little of the coloured plastic to expose the top of one of the blades - just enough to solder a tinned wire onto. Before fitting to the car, I used some insulating tape to cover the soldered joint (but perhaps heat-shrink would be better).

In the second photo you can see my installation, which I am planning to clean up, I'd like to remove the white connector block that I used to join the red wires (what you can't see in this picture is the inline fuse holder, which actually came with the TomTom power supply, which is tucked down out of the way). The modified mini blade fuse is ringed in lime green. You can also see (slightly out of focus) where I drilled the metal bracket to get a good ground. Perhaps not pretty, but it works.

EDIT: Someone has kindly pointed out to me that my installation is dangerous, because the wire I have soldered to the "live" side of the fuse is itself unfused until it reaches my inline fuse, and is a potential fire hazard. I have a piggyback fuse holder on order (from a US seller on eBay), so I will swap it out when that arrives. The reason I didn't use the "fused" side of the new fuse (and I deliberately broke the fuse filament) was that I couldn't be sure that there wasn't a wire attached to the back of the fuse box, running out in a wiring loom to who-knows-where, and I didn't want to make that "live". So my method as documented in this post cannot be recommended for safety reasons. Always consult a competent auto-electrtician before making dangerous wiring mods to your BMW.

[tboudre]

Originally Posted by red-max

Hi Ric,



EDIT: Someone has kindly pointed out to me that my installation is dangerous, because the wire I have soldered to the "live" side of the fuse is itself unfused until it reaches my inline fuse, and is a potential fire hazard. I have a piggyback fuse holder on order (from a US seller on eBay), so I will swap it out when that arrives. The reason I didn't use the "fused" side of the new fuse (and I deliberately broke the fuse filament) was that I couldn't be sure that there wasn't a wire attached to the back of the fuse box, running out in a wiring loom to who-knows-where, and I didn't want to make that "live". So my method as documented in this post cannot be recommended for safety reasons. Always consult a competent auto-electrtician before making dangerous wiring mods to your BMW.

Though the modification of the fuse would not be OK with the NEC, the fact that you tapped the hot side does not violate electric code. They call this the "feeder rule" or "tap rule" that you can go up to 10 ft inside an enclosure before the tap circuit protection and you tap wire can be rated 1/10th the amps of the primary feeder. I couldn't tell you for sure if the interior of a car or behind the glovebox follows the same rules as an industrial electrical panel, though.