First the battery died. I replaced it yesterday and my fuel guage reads "0" remote key does not work, turn signals do not work,horn,rear sun screen and trunk button does not operate...what the ....anyone have any ideas...I down loaded the schematics and see nothing in common with these components?

I know this post is two years old but...

What was the results of your diagnostic?
Did you resolve the problem?

Could be a relay.
On the flip side, I had issues that was high temperature related, with my 85 BMW 325.
During the summer, after a short drive, it would either die or not even turn over, like it was a starter problem. Turns out the main relay was failing after exposed to high temps.

Not an expensive part to replace, so I paid extra for a electronic relay instead of a mechanical.

Typical issues are when the first heavy rains come after summer/fall. Bulbs and other electrical devices fail because of excessive moisture is added to the mix.

Message was edited by: Bimmerman4Ever