While cleaning the gunk off the underside of my engine (1990 745 16 valve B234F) with the splash guard off, I notices a stout wire (in the wiring harness running close to the front of the base pan) that was not connected to anything. It has a washer-type terminal with a flat 90 degree flange on one side that makes me think it should be attached to some bolt that is near a wall, perhaps the base pan which has a raised lip. The wire is not that flexible and there is no obvious bolt nearby to attach it to. I recently did the timing belt so I might have missed putting it back on then but I don't think so. I suspect it is a ground of some sort. The car runs well and the only sensor / electrical problem I have is that the ABS fails calibration on startup about 50% of the time but I attribute that to a pickup sensor problem on the front hubs. The car has a/c (working). Could this be a wire not needed for the B234F? There doesn't appear to be any voltage on the wire, ie it seems to be a ground.

Thanks,
Bill