Radio, CD, Electrical question

[brodee]

When I bought my 540 the radio didn't recognize the CD changer. PO had just replaced the battery the day before I picked it up and said it worked fine before that.

I know there is some process to clear the memory of the radio to reset it but I couldn't find it today doing a search. I pulled the battery cables and connected them together for a while and that didn't do it (maybe I didn't do it long enough?) I also pulled the radio out and put it back in. Each of these caused the code to be entered, but didn't clear the preset memory so I'm guessing it didn't reset anything.

What do I need to do? There is power to the changer and it goes through the CD's fine. I've tried 3 different magazines in it including a new one but the radio never sees the changer.

[brodee]

anyone? Anyone? Beuller? Bueller??