My 850 is being temperamental (imagine) with the a/c intermittent problem that seems so common. Q: Is it possible to get 39-40 degrees if my Refrigerant is a little low? I want to be v. cautious about amt of Refrig that I add, so I need some help. Details:
Works great (40 degree air w/ 80 outside!) for anywhere from 5-20 minutes, then slowly climbs to 60, 70, etc. Then, no a/c. When I added some refrig last week (only about 4-8 oz), it was night and only about 70 degrees outside -- it put out 39 degree air for 30+ minutes and was still going strong when I declared success and tucked it in for the night (ie, no a/c "shut off" like in the 80 heat of day).

Next day, it all started again. Pressure readings seem within that 26-33 range. NOTE: Auxiliary fan works well, runs w/ a/c.

SPECIFICS for a sunny afternoon, 80-84 degrees. Caveats: my Pressure gauge is one of the pre-attached freebies from Intermatic and the Car had been driven for about an hour prior to these specifics (a/c had quit working during that drive):
1. Fan Level 3: started at 45 psi
2. @ 3:00 min: 40 psi, 51 degrees temp probe in duct
3. @ 6:00 min: same numbers
Then, drove it.
4. after 2:00 min of driving, temp probe was reading 60+ degrees and climbing. Stopped to measure: P at about 100 psi (car/compressor were off). Pumped gas and restarted with gauge attached, car in Park.
5. @ 2:00 in Park (in shade): temp back down to 49 w/ P=33 psi
6. Turned fan from 3 to 1: temp dropped down to 42, but P dropped to 26 psi.
7. 2 min later (fan=1), P still at 26 psi and temp was down to 39 degrees! What gives? I've printed and read all postings related to a/c on our forum, but I need a little more help. Thanks in advance!