Speedo and Odometer Dead

[BeemaBoy]

Hi All

Along with my overcooling problem, I recently discovered that my Speedo clock and my odometer have stopped working...the speedo is totally dead and the odometer is ticking at a rate of about 1KM for every 20 or so travelled!

I doubt this would be the wiring because both have failed at the same time and because the odometer still ticks slowly. Is this a failed diff pulse sensor?

Just want to check before I order it from dealers?

Thanks so much
Rawdon

[SPADGE]

I would still check the wiring to the speedo as it could be making a brief connection on the odd occasion hence the odometer going up slightly.

[Brianmoooore]

Can't see anything to suggest it's not the usual internally broken wire to the diff sender.

[BeemaBoy]

The thing is...that one day it was there, and about 3 weeks later when I took the car out first time since then...it was not...litreally as I parked it up it was working perfectly...

There were no signs with the speedo doing anything funny or under-reading...it was just dead when I pulled the car out onto the road...

Do the E30 pulse sensors not have a high failure rate?
Thanks
Rawdon

[SPADGE]

Can't see anything to suggest it's not the usual internally broken wire to the diff sender.

[Jhonno]

There is apparently a couple of solder joints on the back of the speedo that go dry also..

[BeemaBoy]

Can't see anything to suggest it's not the usual internally broken wire to the diff sender.

Hi All

I have replaced the faulty wiring as far back up the harness as I can get to...a good meter or so...
This did not fix the problem. I also tried replacing the diff speed sensor. This has also not fixed the problem...

What would be left to try

Thanks so much

Rawdon

[Brianmoooore]

There is apparently a couple of solder joints on the back of the speedo that go dry also..

[BeemaBoy]

There is apparently a couple of solder joints on the back of the speedo that go dry also..

Thanks for the reply.
Do you have any idea where these joints would be. There are a few places on the back of the speedo and I am not very good with a soldering iron, so would only want to attempt the repair on the faulty ones

[BMWAlpinaC2]

whatever jhonno said

[d6dph]

whatever jhonno said

Pack it in. You have just posted 3 times in quick succession with completely useless comments.

Post whoring will not be tolerated.

[BMWAlpinaC2]

whatever jhonno said

Pack it in. You have just posted 3 times in quick succession with completely useless comments.

Post whoring will not be tolerated.

Ok sorry mate, won't do it again.

Do you accept my apology?

[mrLEE30]

worth also checking fuse 12, have you been playing of fitting a stereo recently?

[BeemaBoy]

worth also checking fuse 12, have you been playing of fitting a stereo recently?

Hey

I checked fuse 12 and it looks okay...have replaced it with a spare one in the fuxe box, but still no luck

The car does have an aftermarket stereo, but this was fitted about 5 years ago...

The problem literally just appeared one day. I parked the car and everything was working. I took it out a few days later and no speedo

Rawdon

[Brianmoooore]

Jack up the rear right wheel, connect a resistance meter across the diff sensor, and turn the wheel. You should see the pulse as the wheel turns.
If all is correct here, remove the instrument cluster, and connect the meter between pins 12 and 8 of the white plug. (brown/red and brown wires). Either spin the wheel again, with the plug pushed back in, or measure the continuity of the wires from these pins to the diff plug.
If all this checks out, take the cluster apart.

[BeemaBoy]

Jack up the rear right wheel, connect a resistance meter across the diff sensor, and turn the wheel. You should see the pulse as the wheel turns.
If all is correct here, remove the instrument cluster, and connect the meter between pins 12 and 8 of the white plug. (brown/red and brown wires). Either spin the wheel again, with the plug pushed back in, or measure the continuity of the wires from these pins to the diff plug.
If all this checks out, take the cluster apart.

Thanks

Will give this a try and report back

Rawdon

[mrLEE30]

Jack up the rear right wheel,

is this viewed from the rear Brian?

[charlie_ogden]

I have the same problem to the letter. was all working now it come back sometimes and flutters about for a bit then dies again? have you had any luck sorting it out?

[hennared323i]

Can't see anything to suggest it's not the usual internally broken wire to the diff sender.

How far from the sensor do the wires usually break?

[Pete-M]

Can't see anything to suggest it's not the usual internally broken wire to the diff sender.

How far from the sensor do the wires usually break?

Mine broke about an inch away from the plug. I replaced a foot or two of the wire just to make sure. It's been fine since.

[Brianmoooore]

It can break anywhere in the last 300mm or so, but usualy closer to the diff.

[hennared323i]

Cheers Gents

[benjy]

Jack up the rear right wheel, connect a resistance meter across the diff sensor, and turn the wheel. You should see the pulse as the wheel turns.
If all is correct here, remove the instrument cluster, and connect the meter between pins 12 and 8 of the white plug. (brown/red and brown wires). Either spin the wheel again, with the plug pushed back in, or measure the continuity of the wires from these pins to the diff plug.
If all this checks out, take the cluster apart.

Will this also work if youve got an LSD OR do you have to lift both wheels.....

[gioris4]

Hi all,

I also have a similar problem. When driving speedo and odometer usually work, but sometimes they die. They may work again if I hit the cluster with my hand, or when passing a bumpy road.
Everything else in the cluster work fine.

Any help appreciated...........

[mrLEE30]

Firstly well done for using the search function!!!

the fact that hitting the dash cures the issue is my main basis for this:

there is obviously an electrical connection issue here, the speedo unit is attached to the instrument board by a couple of pins it is possible they are not making contact due to corrosion. remove the instrument cluster, then remove the ten/twelve screws on rear of instrument cluster to open the cluster. then you can see how the speedo is attached to the board. the pins i refer to shoudl also be obvious, remove the speedo and clean the pins. This is where i would start.

if you need help removeing the instrument cluster let me know and i will find the link on how its done.

[gioris4]

Thanks for the reply.

I got the cluster out and also the speedo. Everything seems ok to me. I bended a little the pins you say in case they are not connecting well. Will also spray with connection cleaner.

I've also read something about dry joints. How can I check if something is wrong? Some of them are a little black. Is that Ok?

[gioris4]

Ok. There was a broken joint behind the speedo. Now it work ok, but on my tests I destroyed the small gear for the odometer....... I have 2 more clusters, all with this gear broken.............

One more question.
Is there a way to make the speedometer work alone, out of the cluster, without having a pulse generator??

[mrLEE30]

the gears are easy to change, did mine in ten mins, the main thing is to find the gears!

as for making the speedo work then you really do need a pulse generator