My 2007 "just a cooper" ragtop has a bike rack and thus the audio backup warning constantly beeps in reverse. I talked to the dealer about how to stop this and he suggested disconnecting the fuse. I had heard that the audio backup fuse also was the fuse for the power steering pump fan fuse. Is that correct?

 

I believe you are correct...most folks with the system have it stop working, and the fuse is blown when the ps fan gets stuck.
It might be a short term fix...like a day or two while you wait for an appointment....

 

Disconnect the beeper, its under the rear side panel on the passenger side rear. Remove the section with speaker cover in all. Disconnect the plug from the back up horn.

 

Do you have any pictures of the panel and what it looks like when open?