air conditioning issue
I bought the vehicle and the ac worked just fine (ice cold). This weekend, I took the car to PHX for an event. I drove down saturday evening (temp was 65 in flag, 90 or so in phx), and had no issues at all. Actually, I didnt even kick the AC on until 2/3 of the way down.
Today was a different issue. I drove to the event at 930a, it was about 85-90 out. The AC worked fine. After the event, the outside temp was about 105. Drove to lunch, and it worked fine. After lunch, I got on the 60 to head home, and it initially functioned just fine. However, after about 10 minutes of driving, it kicked off by itself. I fiddled with the switches, and it came back on, ice cold. This went on for about 20 miles or so (turning off by itself, me f*ing with the switches, it coming back on, then it turning off again).
Finally, I just let it run after it kicked off. After a short period of time (2-3 min), it kicked back on by itself. I tried to track it in relation to the coolant temp and outside temp, and while the temp was still around 100 or so, it followed the coolant needle. The ac would kick on when the needle was just below 1/2, run till the needle was barely past 1/2, kick off, then kick on again when the needle got back to just below 1/2.
As the outside temp cooled down, the ac would stay on longer until it finally stayed on indefinitely (the temp when I got back to flag was 80).
AFAIK the cooling system is in good working order. At one point I was idling in a jam on I-10, and it kept the operating temp under control (a/c cycled during this period). The AC system runs R12, and blows ice cold. All the climate controls work properly.
I did a little research on a few sites, and found a few possible causes (e28 site):
Bad connection at the radiator over-temperature switch
AC fuse melting
Auxiliary fan inoperable
I am still very new to this car, so these possible causes may not even be applicable. Any help is greatly appreciated. My bentley manual is on order, and I have the electrical troubleshooting guide, but I'm tryin to find where to start.