My understanding is that pre-1987 and M3 clusters don't have check engine lights. I decided it would be nice to have a CEL, especially since my knock sensor has been causing problems lately.

The CEL is fed by the #8 wire, which is gray, from the DME. This should be the case for all OBD I 93-95 M50 motors. Check before modifying your wiring harness. The #8 wire carries a ground signal so match it up with a switched 12v and a bulb and you've got a light.

I used the ABS light and ABS 12v feed since I no longer use the abs system. I clipped the #8 wire and attached it to a scrap wire and routed it under the dash to the cluster. So simple, I should have done it 4 years ago.