Electrics dead after sitting

[wcelliot]

Have a bizarre issue... was driving my 1990 325i vert until I blew a head gasket (the repair of which caused another bizarre problem which I'll ask about in the other section) and as a result I ended up parking the car for about a year. I knew the battery was bad when I parked it.

My stepson recently moved back in with us while he looks for his own place and I decided to put tags and insurance back on it so he could drive it vice his big work van.


He tried to charge the battery (he didn't know it was bad) but it wouldn't take a charge. I mention this because it's the only thing done to the car after I parked it running and driving and before my current issue (no pun intended) ;-)

So the day I put tags on it I grabbed a new battery and installed it. EVERYTHING on the car was still dead as if there was no battery there. (I was so shocked I even went back to make sure I hadn't left a post protector on or something really stupid.)

No lights, not power to anything, zero happened when I turn the key to on... nothing.

Except... I was able to test that the ECU relay was getting the expected constant power so there is at least _some_ power getting distributed (though the workshop manual isn't real clear about where that comes from). I can't find any power in the fusebox.

If it was the fusible link (which I haven't checked) wouldn't more stuff still be working?

Is there anything else obvious I should check before cutting in to check the fusible link?

(I have another running E30 here so luckily I can swap stuff in and out for testing as necessary)

thanks!
Bill

[AndrewBird]

There is a junction block in the engine bay, passenger side on the firewall. Power to the fuse box runs from there. Some of those cables are black, despite being power wires (not grounds). One should also run down to the alternator and starter.

[wcelliot]

Thanks!

[reelizmpro]

There's no junction block on the convertible since the battery is in the engine bay.

[e30austin]

Cabrio has no fuseable link. Can you confirm that your ground strap is properly secured? Can you also confirm that the polarities were not reversed, when the battery charger was connected?

I had a slightly similar issue, with a car that had been sitting for a very long time, which turned out to be a failed ignition switch.