Okay here's a new problem I've never heard of: this morning on the way to work (temp in high 80s), while sitting at a red light the temp gauge in my '53 Chevy started going DOWN. Generally it'll go down the road all day long at 190 degrees no matter what the weather, and when it's close to 100 out the temp will very slowly creep up at a red light with the A/C on, but today the temp went from 180 to maybe 160 just in the half-mile from the traffic light to my workplace. I was running late or I'd have driven around longer just to see what would happen. Any idea what is up with that? My thoughts are: failing gauge, failing sending unit, or failing thermostat but I've never had a thermostat stick OPEN?? I won't really know what's up until I drive home at 5:00 today but if something is getting hinky I'd like to figure it sooner than later.