Thanks, Guys! Lots of good info. Especially the link to the other thread that had the FSM info describing the operation of the fan in detail. My 2000, sitting in the evening sun, outside temp of 86, with windows down and AC on recirculate - max - fan on high will only get to around 60 degrees at the center duct. My 1996 in exactly the same location and setup drops to about 52.
Both vehicles have the same charge level and pressure. The only difference is that my 96's fan kicks in immediately. In the old days, the expansion valve getting dirty or defective could make that much temp difference and more, but the expansion valve on the 2000 looks nothing like that of the older models. The system in the 2000 may simply not be as efficient as the 1996 for whatever reason. Anyone else taken the true vent temp to see what you are actually putting into the vehicle?
This is how I tested mine - except for no available shade:
1. Park car in shade when checking temperature.
2. Start engine and allow to run at a fast idle.
3. Turn air conditioner to maximum cool.
4. Insert probe, full length, in center outlet duct or right hand
outlet duct.
5. Allow approximately 5 minutes for accurate reading.
6. Readings of 45o to 60o indicate a properly charged system.
In-car ambient temperature of 75o to 85o should produce
duct temperatures of approximately 45o. Higher in-car
temperatures should increase duct temperatures to no higher
than 60o.