I've just bought a really nice 1989 300TE, all the expensive work has been done, rebuilt transmission, rebuilt head, new brakes, shocks, radiator, etc, etc. A recent drive from Santa Barbara to Phoenix gave rise to a perplexing problem with the climate control :?. It ran fine for about 30 miles, then stopped blowing cold air. I tried turning the unit off and on, but to no avail. When I finally got to Blythe (112 in the shade!) I stopped for gas. As soon as I started the car again, the CC was blowing an arctic wind, and continued to do so the rest of the way to Phoenix! The return trip was similar. It was cold to Indio (about 240 miles) but wouldn't cool upon restart. After a hot ride back to Santa Barbara, I stopped at the supermarket, and when I restarted the car...ice cold CC! Does anyone have any ideas what might cause this? My mechanic says he thinks it is the push button control unit, or maybe a relay. I see that there is a vacuum switch over valve and a three way vacuum valve. It seems that the "mixing" function is what's not working properly. I'd appreciate any help. Thanks!!