E30 Zone

Being as my car was a pre-facelift 87' 325i se I assumed it would have the old Nic'd batteries in. When the temp gauge started to play up and the rev gauge started to stutter/stick a bit (engine was reving freely) I though they'd need replacing.

So I bought a pre-facelift SI board from here, brand new (never used, still old). When I installed it I got a little clock where the inspection light used to be and my revs and temp gauge stopped working.

I'm mildly confused, the only other strange thing was batteries in the old SI Board were the new styled ones, which I assume means someone's changed them already at some point! (Small white lithiam). I thought all SI boards were compatable...

Am I being a spanner?

Eh?? There's no such thing as a pre facelift SI board with lithium batteries.

I meant the board had been swapped before...

Edit: To clear up, it looked like the SI board has been swapped before at one point in it's life.

Boards are all interchangable, and I doubt if there are any working SI boards around still on their original batteries.
Very strange, as, AFAIK, dud lithium batteries shouldn't affect anything other than the boards memory when the car battery is disconnected.
Measure the voltage across each battery.
Someone hasn't fitted lithium batteries to a board designed for NiCds, have they?