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View Full Version : Lidatek E46 power tap -- please help


Plaz
06-05-2005, 02:49 PM
Okay, so I've got my car's interior in pieces... removed the glove compartment and the glove compartment housing... and holy crap the sheer number of wires back there is intimidating.

I've routed my lidatek transponder cables through the two unused "udders" in the rubber grommet in the firewall, and now need to find a wire to tap for power... anyone got any suggestions?

I'm flirting with the idea of just tapping one of the wires running to the power window switches in the center console, since I've got that all apart already as well. (putting the LED and Switch in the ashtray)

Any advice appreciated.

ff
06-05-2005, 03:12 PM
Do you need constant power to this lidatek doo-hicky? If so, my suggestion would be to tap off the cigarette lighter's power.

Plaz
06-05-2005, 03:58 PM
Do you need constant power to this lidatek doo-hicky? If so, my suggestion would be to tap off the cigarette lighter's power.

No, switched power would be better. I don't want to have to remember to turn the thing off every time I shut the car down.

Nick M3
06-05-2005, 04:01 PM
I plugged it into the fuse box. Didn't like the idea of tapping wires.

elbert
06-05-2005, 04:07 PM
I plugged it into the fuse box. Didn't like the idea of tapping wires.

Yep. Get a 0.25 inch spade connector, and plug it into one of the empty fuse slots.
***Make sure you have an inline fuse in place***

I can't quite remember exactly, but one half of the fuse bank is switched differently than the other. That is, one half will switch off as soon as you turn off the car, the other half will switch off after a time period (like your interior lights if you leave a door open). You can check easily with a multimeter.

You can also get one of those add-a-circuit fuse adapters that plug right into an empty fuse slothttp://www.wurthusa.com/project/en/leftnavi/catalog/product.php?path=03.0211.jpg

Plaz
06-05-2005, 04:14 PM
I plugged it into the fuse box. Didn't like the idea of tapping wires.

You don't happen to recall what slot, do you?

I guess that would be better than a tap.

Plaz
06-05-2005, 04:16 PM
I plugged it into the fuse box. Didn't like the idea of tapping wires.

Yep. Get a 0.25 inch spade connector, and plug it into one of the empty fuse slots.
***Make sure you have an inline fuse in place***

I can't quite remember exactly, but one half of the fuse bank is switched differently than the other. That is, one half will switch off as soon as you turn off the car, the other half will switch off after a time period (like your interior lights if you leave a door open). You can check easily with a multimeter.

You can also get one of those add-a-circuit fuse adapters that plug right into an empty fuse slothttp://www.wurthusa.com/project/en/leftnavi/catalog/product.php?path=03.0211.jpg

Thanks... it does have (what appears to be) an inline fuse on the lead that goes to the power switch.

elbert
06-05-2005, 04:20 PM
Thanks... it does have (what appears to be) an inline fuse on the lead that goes to the power switch.

Yeah, but I think it's 10amp minimum. Your Lidatek might have a lower amp rating. I guess you can switch out the fuse, but I don't know if there will be one that is low enough of a rating.

I wired my V1 using the glovebox fuse bank, using the spade connector as I mentioned above. I got a 1 amp fuse inline fuse from Radio Shack.

Nick M3
06-06-2005, 12:55 AM
Thanks... it does have (what appears to be) an inline fuse on the lead that goes to the power switch.

Yeah, but I think it's 10amp minimum. Your Lidatek might have a lower amp rating. I guess you can switch out the fuse, but I don't know if there will be one that is low enough of a rating.

I wired my V1 using the glovebox fuse bank, using the spade connector as I mentioned above. I got a 1 amp fuse inline fuse from Radio Shack.

That's a lidatek provided fuse. It's the correct rating. :p

The HACK
06-06-2005, 02:45 AM
BMW wires are color coded, if you know the codes you can easily decipher which wire or which bank on the fuse panel to tap.

For example, brown is always ground, and brown with black is a higher gauge wire. Green is always switched power, the color indicate how much current it's expected to draw...I think green with yellow is on a 5 amp fuse. Blue is accessory power I think, when you turn the key to the first position this will come on. I think there's a couple of other colors that indicate power per key position, and a few other that indicate amperage.

Plaz
06-06-2005, 07:26 AM
BMW wires are color coded, if you know the codes you can easily decipher which wire or which bank on the fuse panel to tap.

For example, brown is always ground, and brown with black is a higher gauge wire. Green is always switched power, the color indicate how much current it's expected to draw...I think green with yellow is on a 5 amp fuse. Blue is accessory power I think, when you turn the key to the first position this will come on. I think there's a couple of other colors that indicate power per key position, and a few other that indicate amperage.

That makes perfect sense, and is incredibly helpful. Thanks!

ayn
06-06-2005, 01:11 PM
you can use the same wire for the UGDO they use for the V1 hardwire DIY. My cigarette lighter switches off when I turn off ignition so I used that for both Lidatek and V1...

elbert
06-06-2005, 04:07 PM
Thanks... it does have (what appears to be) an inline fuse on the lead that goes to the power switch.

Yeah, but I think it's 10amp minimum. Your Lidatek might have a lower amp rating. I guess you can switch out the fuse, but I don't know if there will be one that is low enough of a rating.

I wired my V1 using the glovebox fuse bank, using the spade connector as I mentioned above. I got a 1 amp fuse inline fuse from Radio Shack.

That's a lidatek provided fuse. It's the correct rating. :p

Gah, misread what he said

Plaz
06-09-2005, 01:07 PM
Okay, so I really want to finish this tonight...

I tried inserting the spade connector into a few of the empty fuse sockets that had only one (brass?) connector, and still don't have power. I'm wondering if those should be providing power. Should they?

Also, I'm wondering if the ground wire needs to be connected not just to any screw somewhere, but if it really needs to connect to the chassis, and therefore the negative battery terminal, to complete the circuit and give the Lidatek power. Does it? (My V1 didn't)

Thanks for any help... I'm not very experienced mucking about with car electronics, as you can tell, I'm sure. :eeps:

Jason C
06-09-2005, 01:12 PM
Okay, so I really want to finish this tonight...

I tried inserting the spade connector into a few of the empty fuse sockets that had only one (brass?) connector, and still don't have power. I'm wondering if those should be providing power. Should they?

Also, I'm wondering if the ground wire needs to be connected not just to any screw somewhere, but if it really needs to connect to the chassis, and therefore the negative battery terminal, to complete the circuit and give the Lidatek power. Does it? (My V1 didn't)

Thanks for any help... I'm not very experienced mucking about with car electronics, as you can tell, I'm sure. :eeps:

Preface: I'd be somewhat leery of messing with any modern BMWs electronic system without some professional help, nice BMW tools, or both.

You need to make sure that whatever screw the ground wire is connected to actually IS a good ground. Sounds basic, but a lot of mistakes have happened with ground wires attached to what looks like a good known ground... that's on plastic or some other non-conductive material.

As for the spade connector, we need more detail. No power whenever, when the key is on/engine off, key on/engine running, etc...

elbert
06-09-2005, 01:18 PM
Okay, so I really want to finish this tonight...

I tried inserting the spade connector into a few of the empty fuse sockets that had only one (brass?) connector, and still don't have power. I'm wondering if those should be providing power. Should they?
Was your key in the ignition? Was it turned to position II (the engine doesn't need to be running)?
If so, keep in mind that each fuse actually has two pins, maybe switch to the other pinhole within the same fuse slot? I can't remember if it makes a difference or not.
Also check if you have good ground.

Also, I'm wondering if the ground wire needs to be connected not just to any screw somewhere, but if it really needs to connect to the chassis, and therefore the negative battery terminal, to complete the circuit and give the Lidatek power. Does it? (My V1 didn't)

You definitely need a good ground. That doesn't necessarily have to be the negative terminal of the battery, but just any screw won't work. IIRC, there aren't many good ground sources in the glove box.
To be sure, you really need to have a multimeter to confirm good ground, if a wire has voltage, etc. It will make this (and any future electrical) project a lot easier. You can get one for only $20 or so at sears.

Jason C
06-09-2005, 01:24 PM
To be sure, you really need to have a multimeter to confirm good ground, if a wire has voltage, etc. It will make this (and any future electrical) project a lot easier. You can get one for only $20 or so at sears.

Yes listen to this guy, a nice DMM is absolutely priceless and won't set you back a lot. You don't need some fancy unobtanium Blue Point/Snap-On model to do DIY tasks.

Plaz
06-09-2005, 01:34 PM
Thanks guys.

The two unused fuse slots I've tried so far only had one "pin" hole... I was hoping to use an unused hot slot, rather than piggybacking on some other slot.

I'm pretty sure the "ground" screw I chose was not really grounded... one of the glove compartment housing screws. That's probably my whole problem right there.

I need a hole saw drill bit anyway... I'll pick up both that and a cheapo multimeter from Sears tonight.

elbert
06-09-2005, 04:39 PM
I agree, I think your problem is from the lack of grounding. Just in case here's a pic of my V1's power wire

http://surface-energy.com/carmudgeons/fuse.jpg

The right (passenger) side of the fuse box is powered only when the key is in position II (on). The left (driver) side will switch on when the key is in position I (acc). So when testing make sure your key is in place.

As for ground, I actually drilled a small hole into the metal frame that surrounds the fuse box, and used a machine screw with a nut to hold the ground wire in place (I crimped one of those circular connectors on the end which the screw passes through). I'd take a pic but it requires some disassembly.

I remember there was one screw already in the glovebox area that was a good ground; however, it was a pita to get to it.
You can also use the flashlight recharger for +12V and ground, but that would require tapping into that wiring which you said you weren't interested in doing.


Thanks guys.

The two unused fuse slots I've tried so far only had one "pin" hole... I was hoping to use an unused hot slot, rather than piggybacking on some other slot.

I'm pretty sure the "ground" screw I chose was not really grounded... one of the glove compartment housing screws. That's probably my whole problem right there.

I need a hole saw drill bit anyway... I'll pick up both that and a cheapo multimeter from Sears tonight.

Plaz
06-09-2005, 04:48 PM
I agree, I think your problem is from the lack of grounding. Just in case here's a pic of my V1's power wire

The right (passenger) side of the fuse box is powered only when the key is in position II (on). The left (driver) side will switch on when the key is in position I (acc). So when testing make sure your key is in place.

As for ground, I actually drilled a small hole into the metal frame that surrounds the fuse box, and used a machine screw with a nut to hold the ground wire in place (I crimped one of those circular connectors on the end which the screw passes through). I'd take a pic but it requires some disassembly.

I remember there was one screw already in the glovebox area that was a good ground; however, it was a pita to get to it.
You can also use the flashlight recharger for +12V and ground, but that would require tapping into that wiring which you said you weren't interested in doing.


elbert, you rock. Thanks so much for the pic. I'll use that slot for my lidatek. (Notice there are no contacts on the top of that slot? That's what I was referring to)

I'll go with a flashlight wire tap if I still have trouble... but is that switched?

elbert
06-09-2005, 05:26 PM
elbert, you rock. Thanks so much for the pic. I'll use that slot for my lidatek. (Notice there are no contacts on the top of that slot? That's what I was referring to)

I'll go with a flashlight wire tap if I still have trouble... but is that switched?

No problem. I wasn't sure what you meant about a one prong fuse slot.

I can't remember how exactly the recharger is switched. I'd check, but my meter seems to have sprouted legs and has disappeared, so I too might be headed to Sears soon. Grr.

I think I had to tap the fuse box because I wanted my V1 on only when the engine was running. You can still use the flashlight wiring for ground if you so choose (but make sure you pick the right wire).

Plaz
06-10-2005, 11:40 AM
Success!

I ended up crimping the little tab on the ground wire around an edge of the metal chassis holding the whole fuse box assembly in place, and duct-taping it. Yeah, it's ghetto, but it's not going anywhere, and it works. :)

Thanks again for the help everyone.

Now my only concern is whether I'll be able to hear the speaker stashed back there in that big white plastic housing, with the glove compartment assembly back in place, over road, wind, and stereo noise. :eeps:

Plaz
06-13-2005, 06:38 PM
That afternoon...

Sequence of events:

1) I'm going, er, let's just say "kinda fast" in a 65 zone, leading a pack of glommers
2) Lidatek and V1 laser alarms go off simultaneously
3) I slam brakes and slow to 70-ish before Lidatek's 5-second window elapses
4) Heart pounding and adrenaline surging, I look UP to see cop at end of overpass, right next to onramp, on opposite side of highway
5) Lidatek and V1 shut up
6) V1 laser alert goes off again... this time alone
7) I'm doing 65
8) Cop pulls out onto highway
9) Heart pounding lots more now as I see flashing lights in distance in rear view
10) Sigh of relief as (Matrix?) a few cars back gets pulled over

ZBB
06-13-2005, 07:38 PM
I didn't catch this thread earlier, but when I needed power for my XM Roady in my e46, I tapped into the cell-phone power under the center console.

I ended up making a little adapter and adding an extra cigarette lighter socket that was burried under the console, where the XM plugged in. The adapter plugged into the stock harness -- I found the pin map on the web some place. The adapter was easily removed when I sold the car...