I'm not sure if this applies to the 'verts, but check for continuity on the small red wire from the battery to the terminal block on the passenger firewall. You can also verify this if the check engine light won't turn on (and if the bulb isn't burned out/missing/removed by PO) when you turn on the ignition or attempt a stomp test. IIRC your battery is up in the front. If that's the case I wonder if that wire is still there, just shorter.
On my old 325is coupe that smaller positive wire has a fusible link that blows & kills power to the DME/ECU. I cut mine out & used a small nut & bolt to pull the two eyelets together, then wrapped it in electrical tape. You should just solder a thick bit of wire. It's an 80 amp IIRC on thick wire, maybe 14 gauge?
The fusible link is a small circuit board that's buried in heat shrink tube about halfway up the trunk alongside the rear wheel well. There is no way to check it (other than continuity) without cutting all that wrapping off. I'll bet you could also test it with a big chunk of speaker wire or about 20' of household wiring.
Topic: won't start, HELP! (Read 4191 times)