I have a Carrier 9200. It was working fine yesterday. But ther was water on the floor. I have seen that before and knew it was a clog in the drain pipes. I turned off unit, pulled out the drain pump, cleaned it. flushed the pipes and put the pump back on. I turned on the unit and nothing.
With the switch closed the LED says the unit is in working order with no error code. The thermostat has power and reports being on hold. it does not respond to Air or heat.
Unplugging connectors and trying to see if something might be shorted makes no difference until you disconnect 2 red wires that run to a brown circuit type board attached to the inside of the unit above left to the black compressor. When these wires are pulled the unit will come on and the blower will work. the LED reports 13. Although the blower is working it is not producing any air conditioning. As soon as you reattached the 2 red wires, the unit stops working. These wires are attached to PL1 4 and 6.
The fuse is good. Circuit breaker is not tripped.
Im an engineer so I read schematics and understand the components, but dont know where to start since the system reports everything is OK. Obviously it isnt. Note: the air flow is not blocked.