I need to know what wire to tap for speed sensor in a 97 bmw 540. As close to the glove as possible would be great. I'm hoping there's something easy to tap off the back of the fuse box in there.

3/19/2008 7:13:27 PM

what are you doing?

3/19/2008 7:54:14 PM

I need a speed signal for a NAV unit I'm putting in

3/19/2008 7:57:20 PM

just go to http://www.avic411.com and search for your car there. even though that might not be the radio you are installing you can still find the wire you are looking for.

3/19/2008 8:21:29 PM

yes..

did you find what you needed yet?

3/20/2008 2:05:28 PM

I thought that unit would just use the GPS signal, I know my avid N2 did back in the day, VSS wire was a waste of time

[Edited on March 20, 2008 at 3:08 PM. Reason : nvm, forgot it's useful for a backup camera--otherwise my statement still stands]

3/20/2008 3:08:27 PM

yeah, I still havent found it. I posted a question on that board but no answers yet. been fabricating the cage so far

3/20/2008 6:31:51 PM

are you using a backup camera? i'm tellin ya man, if you aren't there's no point of the VSS sensor

[Edited on March 20, 2008 at 9:08 PM. Reason : and even then the last one i had had another wire to hook to reverse lights to sense reverse..]

3/20/2008 9:07:34 PM

I'm going to have a back up camera yes, I found one with infared/nightvision so I can see stealthy humans and what not. for reverse I'd tap the reverse lights though. I tested gps tonight without VSS and it seems fine, but you have to wonder why they put it there if it's so apparently useless.

3/21/2008 9:17:43 PM

yeah, gps doesn't rely on the vss. it's getting everything from satellites.

i'll disclaimer this with i don't know much past the basics about audio stuff, but the only thing i can think of the vss being used for would be to keep you from watching anything in motion (including keeping you from entering anything into the gps).

3/21/2008 9:26:12 PM

the N2 and newer wont let you watch anything when the GPS says your moving without doing some soldering on the control board (pretty easy), the N1 would however. The VSS (to my understanding) is used mainly when GPS signal is lost to approximate your position. It also use a gyro sensor.

3/21/2008 10:27:39 PM

manual or automatic? the bmw wiring diagrams suck, but i can probably figure it out for you

3/21/2008 11:09:53 PM

on my avic-d3 i had to hook up to the vss wire even though it does display speed from the gps. if i didn't hook up to the vss then it wouldn't play dvd's and the bypass i did to allow it to play dvd's while driving wouldn't work.



[Edited on March 22, 2008 at 7:33 AM. Reason : -]

3/22/2008 7:27:52 AM

^ i thought most of them just used a parking brake switch wire you could easily ground

and if it used the vss, if it got no signal it should work, so whether its stopped or disconnected it doesn't know the difference

3/22/2008 8:31:33 AM

yeah, it's a manual. I'll probably just tap reverse light unless there's something much easier since I gotta put the cam back there anyway.

3/22/2008 10:53:53 PM

Quote :

"^ i thought most of them just used a parking brake switch wire you could easily ground"

they used to and some other models will but pioneers new ones sense movement via GPS and actually use that to know that you shouldnt be messing with a DVD or whatever else.

There's a mod where you solder two pins together or break one off, I can't remember which and it makes the unit not care anything about what you do vs movement--I did it back in the day and it worked great

3/22/2008 10:57:59 PM

Quote :

"The VSS (to my understanding) is used mainly when GPS signal is lost to approximate your position."

good point. didn't think about that.

Quote :

"i thought most of them just used a parking brake switch wire you could easily ground"

yeah, that's what all the older stuff and i assume still some of the new stuff uses as the "safety" feature. it's my understanding (like has been mentioned above) that the latest models, especially the higher end name brands, are incorporating more complex methods of preventing gps inputs and visual media while moving.

for example, most if not all factory systems use a speed input to lock out functions, whether it's from the vehicle itself or externally from the gps. i think part of it is for safety/liability, but another big part has to be to promote the use of paid services like onstar that can input directions for you with an in motion hands free call.

3/22/2008 11:06:17 PM

well I did the work around on my head unit (d3) just because it was easier than wiring the parking wire. all you do move the mute wire up 1 notch in the harness and then ground it and the parking wire. I can watch dvd's while I drive. I buttoned everything up because I was tired of looking at it all hanging out and not being able to have a passenger. and I ran the lines I needed for speed and reverse into the glove so I can tap em if/when need be. I gotta start working on fabbing a face bezel now.

3/23/2008 9:04:02 AM

yeah, i did the bypass on mine too. i also installed the pioneer back-up camera. i can either turn it on manually or it comes on automatically when i put it in reverse. talk about hooking to a trailer easily!



here's where i mounted the camera

3/23/2008 9:12:36 AM

that's cool, I had a cheapo backup camera on my dump truck once upon a time for that very reason... i sucked at judging distances when I was hooking up a trailer (which was about once a day)

oh, and it was wireless on a very standard frequency--I'd drive by peoples houses and see baby monitors and or their security cameras all the time haha, it was pretty weird looking at peoples babies

[Edited on March 23, 2008 at 9:19 AM. Reason : asdf]

3/23/2008 9:14:03 AM

I realized without cutting up my bumper, there isnt a whole lot of point to a camera that will have the same view as my mirrors. I think I'll just put a tv tuner in that input

3/23/2008 1:26:16 PM

^^^damn, that's sweet. i didn't realize they were so clear now, the last one i saw was useless for anything but seeing major objects like people, poles, or whatever. i can't wait to get mine in my suburban. that'll make hooking to the car hauler a breeze. i can get within a few inches of it usually, but getting it just right under the coupler can be a pain by myself. you're sure as hell not lifting or shifting that heavy bastard anywhere.

3/23/2008 3:27:41 PM

and that picture really doesn't do it justice. it looks dark in the picture. it looks really good irl and it is surprisingly bright at night. i think the camera is 0 lux or whatever the fuck that is.

3/23/2008 8:05:50 PM