Cluster issues, First Odometer, then Speedometer

[P Arkus]

Hey guys, I'm looking for help diagnosing a little cluster problem I have. Shortly after I purchased my E30, the odometer broke. Everything else worked fine, Speedometer, Tach, Temp & Fuel Guage, and all the lights on the cluster. Only the odometer and trip meter failed. So I did a bit of searching around and realized the odometer gears quite commonly fail over time and especially over drastic weather changes.

So I ordered a new set of gears (Pain in the ass since its a European Motometer cluster and reads in KM/H), and installed them. Upon taking apart the cluster and pulling the old gears out, one of the gears had 3 broken teeth in a row (plus other various teeth here and there). Replaced the gears, spun them, and everything looked like it should work great (in theory). Put the cluster back in the car, now the speedometer AND the odometer dont work.

This is the part that has me stumped. I checked all the fuses, used a volt-meter to check the power going to the cluster, everything seems fine. Only part I haven't checked is the speed sensor on the diff, as I dont believe the odds that in the time I was pulling the cluster, for some reason the sensor went bad on the diff.

so I believe my problem is in the cluster/speedo guage. I checked all the solder points, everything seems to be fine. Nothing seems broken on it. Can anybody help me with this?

I'll be swapping a friends cluster in about a week or so when he gets back into town just to be 100% sure its the cluster, but in the meantime is there anything I can do?

All tips and opinions are appreciated. TIA!

[jlevie]

Did you remember to to connect the green connector (or the wires that plug into it)? That is the speed sensor connection.

[P Arkus]

Do you mean this green connector that is circled?



I was under the impression that this connector was only for Cruise Control (which my car does not have). When I pulled out my cluster initially, there was nothing hooked up to it. I only had the white and blue connectors (the yellow connector is for OBC, which again my car is not equipt with).

Am I missing some wires in the back of the dash somewhere???

[jlevie]

That connector is where the speed signal from the differential connects. It can have a second wire.

[P Arkus]

Hmm, I wonder if it just fell off when I was trying to get the cluster out. I will check this out tonight. Thanks for your help!

[efficient]

Anyone know what the black wire that goes into the green connector do or which slot it goes into of the 3 on the green connector?

[jlevie]

All of the connectors in the green plug are common.

[P Arkus]

Alright so I went out to the car and took some pics. Here are the wires that seemed to be hanging loose. I'm guessing these are the ones that need to be connected to the back of the green connector.




And here is a pic of the green connector.



Now I know all the connectors in the green plug are common, but there are 2 connections for wires in the first 2 pics I posted. Do both of these get connected to the green connector? If so, where does wire connection on the left go? I found the wire connection on the right fits into the right side of the green connector pic, but not exactly sure if the connection on the left should be plugged in anywhere or just hanging loosely. Again all help is appreciated!

[jlevie]

That doesn't look right. I've never seen a speed sensor wire with two connectors on it.

[dnguyen1963]

By looking at the shape of the connectors, I think the left one was an add-on for something else...maybe an aftermarket odometer (replacing the broken one?). I would leave it hanging.

[P Arkus]

Damn, thats not good then. Unfortunately the car is on summer tires and there is quite a bit of snow on the roads so i'm a bit hesitant to take it out and test it. I did a little test last night in the driveway and just let the rear wheels spin on the ice, but the speedo didnt move. I'll have to take it out when the streets are empty and really give it a better test run.

Thanks again for the help guys, i'll check in when I have some more solid evidence!

[P Arkus]

Alright, so I tried the cluster out again. Plugged everything in, plugged the little black wire (the right connector) into the green connector plug (tried 2 different slots), took the car for a bit of a drive, and still nothing. No speedometer or odometer, but everything else works fine.

I'm completely stumped at this point!!! I'll be checking the sensor at the differential today (even though I still dont believe the coincidence that the sensor at the diff crapped out as I was pulling the cluster the first time), and i'll also check the power going to that black wire and make sure all is good there.

Is there any other troublespots I should look for? Like I said, i've checked the power going to the blue and the white 26 pin connectors, i've checked all the fuses (will do a triple check with a test light today). Is it possible that something fried on the speedometer guage itself? Any help is appreciated at this point as I hate dealing with problems that I just cant diagnose! Thanks again everyone!

[dnguyen1963]

I would take the cluster out and exam the board for any crack in solder under a magnifying glass. These boards are old.

[BROKINBIMMER]

Any luck? I'm in the same boat. No speedo, No odo. The reason that I disassembled everything was to replace broken odo gears. After replacing them, now I have no speedo, just my luck. All my conections look good as well...

[P Arkus]

No luck yet unfortunately. I'll keep updating this thread so that hopefully others in the future can make use of it and hopefully diagnose the problem faster.