I have just bought a used SI board for my 1987 326is. The problem is that the new and old boards seem very different: the new one has lithium batteries and seems to be from a 325e. The shape of the board is also different, where mine has a cut out part for the insertion of a second board (which enters from the front of the cluster) the new one is square and does not have the space for this second board. The new board also seems much simpler (in terms of resistors and chips) than the old one and has different pin patterns where it inserts into the dashboard.
Will it work, or do I need a different older SI board with the NiCd batteries.
Thanks in advance!