wrong speed sensor?

[TimbyMaTombo]

Hey everyone, my speedometer, odometer, trip, and mpg haven't worked since I bought the car and yesterday, I replaced the speed sensor in my 88 325is with this part http://www.ecstuning.com/BMW-E30-325...nsor/ES171916/ The sensor I took out looked different with the two prongs not being the same length, but I figured that it should be fine. After replacing it, it still doesn't work, so could I have bought the wrong sensor? The website says it's for the 325ix, but I didn't think it should be any different. Did I just waste my money on the wrong part?

Thanks everyone,
Peter

[nando]

the 325ix is different, and the length does matter.

[TimbyMaTombo]

Well that sucks... I should have checked that before I bought it, but oh well... I learned my lesson, so I guess I'll see if anyone needs a brand new iX speed sensor.
Thanks

[agent]

Are you sure it's a speed sensor issue and not a cluster issue?

[nando]

the speedo would have to be totally fried, usually only the odometer breaks because it's mechanical.

[TimbyMaTombo]

I'm not sure, but from what I've read on these websites, it seemed like it was the problem, and I was hoping it was since it'd be the easier fix.

[nando]

also more likely than the sensor itself is the wires to the sensor, they get hard and break. you could try splicing in a new peice of wire for the last couple feet, you can get them with the pins already attached. then try your old stock sensor.

[agent]

the speedo would have to be totally fried, usually only the odometer breaks because it's mechanical.

Agreed, though the key word there is "usually." My speedometer does not work when I first get in the car, though it usually ( ;) ) starts working after between 15 and 30 minutes of driving. The odometer has brand new gears, but when the speedo isn't registering, the odo isn't recording miles and the MPG gauge is either pegged to the left (off-throttle) or right (on-throttle).

I had another cluster in the car while I was working on the car and rebuilding this one, and it did not exhibit this behavior. I have purchased a rebuilt board from Greg to see if it alleviates the problem with this one.

[TimbyMaTombo]

Is there any way to check which one it could be other than replace it until it work? The sensor I took out doesn't look damaged, just a little dirty. The wires did look kinda old, which is to be expected I suppose... Where would I find the wires?

[nando]

it's one of these 90 degree connectors:

http://www.realoem.com/bmw/showparts.do?model=1593&mospid=47324&btnr=61_2486&hg=61&fg=15

either #4 or #8 (.5-1mm with cable), I can't remember.

[Gregs///M]

I suggest you go ahead and replace the speed sensor with one intended for your car. SI board battery failure usually always affects the tachometer operation more than anything. If your tach works fine, I would go ahead and assume your speed sensor is shot or wiring to it.

Patch it all back together and go from there.

[nando]

yes, and the SI board has nothing at all to do with the speedometer. :)

[agent]

Where does the speedometer get its power?

[nando]

from the cluster

[agent]

When discussing the "SI board" it's my understanding that we're talking about part #6 in the diagram HERE.

When discussing the "cluster," specifically as it pertains to where the speedometer gets its power, is it not that same board?