It makes noises when it's in park, of all things

I’ve had occasional trouble with the speedometer not registering my speed. It’s like the needle waits to “warm up.” Rarely, it has stopped working in the middle of a drive. I don’t know if that’s related to my real issue:

Saturday it sounded rough when starting and while in park - but not while in gear or driving (almost a grating noise). Then I noticed the radio and A/C fan weren’t working as I drove (just a hint of cool air). The lights seemed fine. I stopped for an errand and the problems were gone when I returned and restarted it. What gives?

Since the accessories you mentioned are tied to power through the ignition switch that may have a intermittent connection.