I've done all the basics that I can think of in terms or checking that the coils are clean, filters clean, electrostatic cells clean. This it the first time I have seen any problems. The unit is 15 years old, has been a great performer with low cooling bills, thanks to the VS blower and 2 stage compressor. What is happening now is the unit goes into A/C start-up on low, starts to ramp up to high then does a stutter or shutter (thump) and shuts down, restarts the ramp up all over again. (1) Can't be overheating because the motor is not hot, (2) does this from being off for awhile also, (3) NO blockage under unit, even removing all cells and filters does the same with door in place. (4) the motor spins by hand normally per the manual hand turn check.
Now here is the kicker, with the service door off and safety switch closed it will ramp up to full speed and cool down to cycle at temp and slow down and turn off and wait for next cooling demand.
Unit is located in a utility closet adjacent a laundry room with a gas dryer, so I either run the A/C while continuing to troubleshoot (service door open, closet door open) to avoid 105+ heat outside or shut system, power down, to run dryer to avoid any possible draft issues for safety reasons. Both units have electronic igniters, so it's not a lit pilot situation, just precautions.
Even did a cleaning on the coil in-place, but short of removing the coil to further inspect (which I'm not prepared to do) I can not see any reason for the failure to run at high blower speed with the door on. And since it cools correctly and the Freon levels look within range at the compressor I really don't think there is a compressor issue or that the coil is impeding air flow. Unlike some units on the Amana the gas furnace burners are between the blower and the A-frame coils so looking up from the bottom to view the inside is impossible from what I can tell.
Seems like a pressure sensor somewhere is reading one way with the door on and another with the door off, but where is the sensor? I though the gas heat, air flow sensors only had an effect on the heating burner applications, flu and not the A/C functions in cooling mode. But maybe I'm missing something here?
If this were an appliance problem I'd be done by now, but this is more than a simple fridge/freezer compressor issue so I could use a few pushes in the right direction.