The AC on my 97 E320 began blowing hot on the highway,
so I glanced at the temp gauge, which was maxed. A few
minutes later, the AC began blowing cold again, but the
temp gauge appeared no longer functional, it was at the
bottom. I'm considering just replacing the thermostat,
to see if the problem goes away, rather than leaving the
car for service. Is this a reasonable course of action?