I own an '84 323i and my speedo is driving me absolutely crazy. I first started having problems about a year ago, were my speedo would sometimes work and then all of sudden just stop working and drop to zero and then maybe 10 min later would start working again or sometimes not start working till the next day.
I decided to pull the speedo out and have it tested by a VDO agent and they showed me it working fine. I then went on to test the continuity of the wires running from the sensor in the diff all the way to the pins on the instrument panel circuit board and they are all fine. Then thinking it must be the sensor it self, I replaced it with a new one but to no avail. The next step was to replace the Instrument panel circuit board but that did nothing either. The service indicator board has also recently been replaced and the batteries seem fine. So I need some help!
* on the instrument panel circuit board there are 5 pins which connect to the speedo, can anyone tell what each of these pins are for (voltage, pulse signal etc)?
*Also is it possible to wire up the speedo by running wires to sensor in the diff and to the battery?
Any help would be greatly appreciated as you can see this is getting quite costly for me, Thanks