Anti-theft Radio... How to reset?

[TUSE]

My Dad just bought a 91 K100LT with the factory BMW radio (apparently with the anti-theft option). How do you reset it (It turns on, it shows some numbers (654 and a little 3) and the speakers crackle a little when her turns the bike on, but the radio does not seem to want to work. He thinks that with the tape deck he can barely hear something in one speaker (of-course, now he can not get his tape back out).
Is there a code, if so, where/how do you get the code and how do you input it?

Thanks for any help,

TUSE

[mobygrape]

The bike should have come with the radio code on a card with the owners manuals. If there isn't one, a BMW dealer can input a code number found on the radio chassis into the BMW dealer website and get the proper four digit code. If the wrong number is entered, holding down the "band" button will clear the display and allow the code to be entered again.

[RCD]

I had this same issue and have found your comment very helpful. Now I need to know how to keep the code entered. Every time the bike is powered off, the code is lost. I don't mean when the radio loses battery connection. It maintains electricity to the radio. How do I lock the code?

[muso1958]

must be losing permanant feed to radio . there are 2 pos conns one switched thru ign 1 permanant to maintain radio presets and radio code

[dzimbric]

That how they are connected. It is a PITA but my 89 and 96 both have to be reset everytime you start the bike. I yanked the radio in both and listen to my iPod through earbuds since you cannot hear the radio at speed.