Dead speedo

[porkkis]

My speedometer just died
So did the odometer and rear diff does not disengage automatically.
Has anyone got any clues what might be wrong?
I already took the sensor connector off a few times but didn't help.
Dead sensor or could it be a wire problem (signal to ground?)?

The car is a 5spd one, but probably all related systems are similar to 6spd.

Afterall she's running now. I was able to get 39kms to the odo until the first problem occured
Still have to get a straight bonnet and get it painted and things like that. I'll post the whole story to the projects or cars section in the near future.

[Martynf]

Porkkis,

A wild guess for you here, I reckon its the gearbox mounted speedo distance sender fallen apart inside!! they always seem to fall apart!

If this doesn't work, then the speedo + the odo will stop working straight away, and also the rear diff may not disengage automaticlly because if the distance sender has packed up, then the car doesn't think it is moving!! so it won't turn off as it never thinks it has reached the speed to turn off!!

Part number of the distance sender is 012 409 191D, they are pretty cheap and easy to change, so might as well do it!! in the UK they are £13+vat.

I bet it is that!
Martyn

[porkkis]

Thanks,

I think I know a bit about the system but there are still questions like does the signal go straight to the speedo unit and does it manipulate it somehow and then pass it to the other control units like the rear diff unit or does all the units get it straight from the sender..?

Strange thing was that it came back for a while nearly 100km later. Just a few kms of straight highway driving and then it died again. Could mean that the sender isn't totally dead or the whole thing could be in the wires or in the speedo if it manipulates the signal.

[Martynf]

I'm pretty sure the distance sender feeds all the info to the dash, then the rear diff takes a signal from the dash to tell it to turn off.

The speedo coming back for a short while, tends to back up the sender is just starting to fall apart. When they get old, they just plain wear out and don't engage properly. I jolt or even just changing gear may bring it back working for a short while.

Have you had a look at Paul's S2 central site to see if he has any wiring daigrams for this?

Martyn

[porkkis]

Ok, I checked the wiring diagrams. After a while of guessing what the Norwegian terms could mean (with a basic skill of Swedish) seems that there is a connection point somewhere and all the units get the "raw" signal. So one wire anywhere that grounds the signal could be the reason.

First I'll try to find the connecting point and disconnect all but speedo output and go for a test. If the speedo is still dead I try to listen the signal (yes you can do that!) and then I'll get a new sender if necessary.
The cost is not the problem but I really don't like the idea of changing it as I've been working on the car for 6 months now... and the sender would have been very, very accessible when the engine was out.

[Martynf]

Sounds good to me. Hope you find it pretty fast
Martyn

[s2driveruk]

Porkkis,

getting the sender out is a doddle even working under the car - hell i managed to change it - anyone can!!!!

I though changing mine would cure the intermittent speedo but it didn't so i have a known working one (the old one) sat on a desk at home if you want it?

Cheers,

David