Tach Issue - Idling at 0

[ohthejosh]

84 323i grey market

When car is idling it sits at 0, but it'll work when you rev the engine, not sure how accurate it is when its actually working considering its idling at 0. Any reason as to why it's doing this and is there a quick fix for it?

[ohthejosh]

Bump

[E30NJ]

There are little contact springs that go to the board. 99% there is a little surface rust or dust messing up the connections. Did you ever figure it out?

[Gregs///M]

you need to replace the SI board. The batteries are dead. If you don't do this right away, the batteries will leak and the whole cluster will need to be replaced.