E30 Zone

my speedo only works when it feels like.... ive changed the sensor in the diff and checked the wiring from there to the conection block under the rear seat. does any one know where it goes from there and what colour is the wire at the speedo side and how to test for a signal???? thanks... bjdp

You say you've 'checked' the wiring from the sensor - have you actually replaced it.

Over time the wire becomes brittle and will break within it's sleaving, so externally there is no visable damage. 99% of speedo woes can be fixed by simply replacing the connection plug and about 20/30 cm of the wiring.

I have a non working speedo and im guessing the connector and wiring needs replacing, where can i get some to replace it with?

Cheers

i put a seperate wire from : i by passed the junction block under the rear seat just in case it was that connection (soldier two wires by tapping into the original sensor wires) and took it down to the conction on the rear diff. i didnt change the connection plug i cut the old wire off and soldier the new wire onto the original one.... maybe i'll try a new plug...thanks guys

I've replaced the last meter of wiring on mine from the sender and the speedo is still only working when it wants to

In that case, turn your attention to the speedometer in the cluster. Dry (cracked) solder joints have been known to occur on the speedo circuit board near where the pins that plu into the main board are fitted.
The sensor in the diff. is a simple reed switch, so a meter switched to 'ohms' will show alternately zero resistance and infinite resistance as the rear wheels are rotated.