Speedometer gone crazy

[ausie320]

Hello All. I am hoping someone has come across this problem before. My 91 E36 320i speedometer recently decided to go crazy. When I start to accelerate the speedo needly zooms up to 98kph and stays there not matter what spped I am actually doing. (I wish I had the acceleration proported by my speedo)
I had this problem a few years ago and it fixed itself. ie there one day gone the next with no intervention by me or anyone else.
I have checked the sender for continuity, seems OK. Voltage at the sender is around 5V?? seems low.
All other guages work as advertised. My model is stock standard, no cruise etc.
So, any ideas? Will I have to mortage the house for a new guage, is there another blackbox in the circuit that could cause this, could an earth leakage be the culprit???

Over to you Beemer Lovers.
regards
ghead Aussie320

[El Presidente]

Sorry to say, but you may have to start looking for a new guage cluster.

[thekid]

have you checked the speedo cable? when you check make sure that is' not dry, it may just need to be re-greased.

[ausie320]

Hi Everyone,
Thanks to those who replied.
I resolved the problem. I noticed that one coil of the guage was not working, therefore problem lay in the cluster.
I removed the cluster (two screws in dash, unplugged three connectors, rotate and squeeze through the top of the steering wheel) and separated the electronics from the guages (three torx screws and undo two levers either side). All guages tested fine electrically. I noticed that one of the long contacts on the speedometer meter had excess solder resin and the insulator cup was distorted. Removed the resin and trimmed the insulator. Put back together and Bob's your uncle.
Hope this may help someone in the future.
regards
Aussie320