Ron,
My radio is a Blaupunkt but I think it is original for my 91 Syncro.  For
what its worth, exact directions from manual follow:

Preparing the Radio for Operation
Every time the radio is disconnected from the car's power supply, the batter
is disconnected, or even if the radio fuse blows, the radio must be recoded
to make it operational:
1.  Turn radio on-turn volum knob (1) clockwise; car ignition must be on.
"CodE" is displayed in the radio display (3)
2.  Press one of the first four preset buttons, "CodE" will disappear, and
"0000" will appear in the radio display.
3.  After "0000" is displayed, enter the security code which is shown on the
front of this manual using the first four station preset buttons (16).  Use
button 1 to set the first digit of the four digit code, button 2 to set the
second, etc.  Press each button the number of times needed to enter that
digit.
4.  Finally, press station preset button 5.  Now the radio frequency will
appear in the display and the radio is ready for operation.
Note:  Entering the security code must be done within 1 minute.  If not, or
a false code is entered three times, "CodE" will appear in the radio
display.  Repeat the entire procedure again.

Good luck.

Jim
91 Syncro AW
----- Original Message -----
From: Scarlett Semko <damosem@MAIL.MCO.BELLSOUTH.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, June 06, 1999 9:03 AM
Subject: Help, Radio Locked

> Volks,
>
> I'm reposting this because I still need some help here.
>
> I just purchased a original equipment radio (Heildeberg "V"), formy
> Vanagon. It is locked.
> The proceedure and code in the Bently is for a Heildeberg VI radio (will
> not work for me). The radio I have is out of a 1986, so I assume that
> any 1986 thru 1990 OEM radio would be the same.
>
> Supposedly, the proceedure and code is in the original books that came
> with the vehicle/radio. If someone could check to see if they have the
> information I would appreciate it very much.
>
> Thanks in advance,
> Ron Semko
> Radioless in Orlando, Florida