Computer screen blank after battery failure

[dan.sorenson@pobox.com]

After the battery on my 1989 535i died, with the doors locked, I charged the battery using the positive cable on the starter motor and the doors opened, but the computer screen is now blank. The computer is not dead because I can get the readouts on the screen below the speedo/tach cluster using the turn signal stem to change functions.
What's up?
By the way, I (supposedly) got the radio code for my factory radio from the dealer so I could reset that after the battery was recharged, but it still gives me a "CODE" reading and entering the code I got from the dealer doesn't fix it.
Anybody know where I can get the right code, or any suggestions? (I've done the wait an hour and 15 minutes routine, entered the numbers after the beep, etc.) The $90 an hour "geniuses" have been of no help, as usual.
Dan Sorenson 1989 535i and 1978 R100/R Tucson, AZ

[Bill R.]

bulbs or lighting circuit on the obc itself. I would first remove the radio then copy the numbers down again, then while the radio is out pull the obc and unplug it, wait a couple of minutes and plug it back in.. IF the display doesn't work then I would take a look at the bulbs. After writing the numbers down from the radio I would go back down to Mackey's with the numbers and make sure they gave you the right code. Then turn the key on wait one hour with it on and take your next three attempts with the code.
Bill R.
Tucson.










After the battery on my 1989 535i died, with the doors locked, I charged the battery using the positive cable on the starter motor and the doors opened, but the computer screen is now blank. The computer is not dead because I can get the readouts on the screen below the speedo/tach cluster using the turn signal stem to change functions.
What's up?
By the way, I (supposedly) got the radio code for my factory radio from the dealer so I could reset that after the battery was recharged, but it still gives me a "CODE" reading and entering the code I got from the dealer doesn't fix it.
Anybody know where I can get the right code, or any suggestions? (I've done the wait an hour and 15 minutes routine, entered the numbers after the beep, etc.) The $90 an hour "geniuses" have been of no help, as usual.
Dan Sorenson 1989 535i and 1978 R100/R Tucson, AZ

[Paul in NZ]

this happened to me too when i replaced my battery.I had the display on the dash but the obc was blank....came back tho.....wait a day or two.

[dan.sorenson@pobox.com]

Paul,
I like the self-healing concept, as it matches my mechanical/electrical skills. But it's been nearly a week and it's still blank. Do you know what the CODE button on the OBC is? I was wondering if there was a separate code for the OBC.
Dan S. in Tucson, AZ

[Paul in NZ]

hmmmm,mine came back within a few minutes....matches my skills too ;),CODE on the OBC is an immobiliser system,dont forget the PIN you use!