Unit is a York GM9S080B12UP11G.
When switching thermostat to cool, the system activates the compressor fan. Also, I can hear gases moving through the pipes running to the compressor. However, the blower fan never comes on, and the system blinks an error code (4 red blinks) that corresponds to "Limit switch stuck open" on the chart attached to the inside of the unit.
I've tried temporarily closing all 3 limits that I could find: the main limit situated near the heat exchanger, the limit inside the box where the jets are, and the limit attached to the draft inducer.
I'm beginning to think that it isn't really a limit problem, especially since this is with regard to A/C, not heat. Heat, by the way, has been working just fine. This is the first time attempting to fire up the A/C this year, since it reached 85 today.
Does anyone have any ideas of what to try, or what the underlying problem could be?