I had to have my blower replaced (2005 roadster). The control unit is part of the blower assembly so the whole thing gets changed at once, but after I got it back the fan behaved intermittantly erratic. I took it in and they replaced the resistor pack and all has been fine since. Mine was covered by warranty (or maybe the extended warranty inssurance that I also have) so it didn't cost anything to fix. You might check on the warranty details.

Ste7of1