Thanks - I've been doing that and have gotten some good info from here. In light of the issue with the headlight, I'm starting to suspect that it might be a fuse - as someone mentioned in another thread. From what I've read, the most common issues seem to be the fuse, relay control and air pump.

I'm probably going to end up taking part of the day off from work today and taking it to a mechanic. I have to get this problem resolved.

Thanks again, everyone, for your help.