87 325 eta si and cluster problems

Howdy all,
I just found an 87 325e for my ladyfriend about 2 weeks ago and have solved all it's little problems except for the instrument cluster. The service interval lights don't work (although I reset them after performing initial maintenance) MPG gauge doesn't work, but every once in awhile, it will fluxuate wildly and when it does the engine begins missing terribly. Also, we just lost the tachometer and the turn signals of all things. On her advice (she has owned a 318i) I ordered a replacement ECU, but that has had no effect on the problems. I'd appreciate any help from yall.
F

You probably need to replace the rechargeable batteries on the service indicator board. The ECU has no effect whatsoever on turn signals or the MPG gauge. Go to bmwe30.net for more and better help.

Thanks for the reply, but I've already replaced the batteries. I did that early on when I first took apart the cluster to find out why the Odometer wasn't working (broken cogs on gear). Any other ideas maybe?