I hope there are no vintage AM-FM cassette thieves reading but ....

Car is 1988 560SK with original radio-cassette. I had occasion to remove my steering wheel recently. It is air bag equipped and cannot be safely removed without diconnecting the battery. After reading a number of posts and not having the original code, I was spooked by the recoding issue so I placed a call to Becker in New Jersey. This is thier story:

The Becker Grand Prix in my car and others of similar vintage will display a row of dashes after power is reconnected and the radio is turned on. It will not work until recoded in some arcane way, probably by Becker.

I was told by the Becker rep that if one removes the radio first and unplugs the 5-pin connector from the back of the radio AND LEAVES IT OUT, the radio will operate normally when the battery is reconnected. The 5-pin plug may be removed before or after the battery is disconnected so long as the radio is not turned on before it is unplugged and the 5-pin NOT replaced.

Bottom line is that it worked. I thought this would be useful information for some of you. Unplug that connector and leave it out. Of course, it will make it easier for someone to steal that 20 year old radio.