I'm getting ready to strap a bomb to this 2000 (528i). We've been having issues with the a/c not working or working when it wants. It was turning on and off constantly, not working at all, and just being a pain. Now that the weather is getting warmer its a bigger issue. Read that the FSU may be faulty and tend to fail pretty regularly. Replaced it yesterday and it did not help. Is there some sort of programming that needs to happen when replacing the FSU?
What's the next likely culprit?