I do not know what was done with the wiring of the red, brown and blue control wires but it involeved the indoor blower relay.
We by passed that relay to allow the blower to come on with a call for cooling (R to Y).
With the relaay bypassed and the compressor, outdoor fan and indoor fan running we should have a discharge temperature of at least 15 degrees cooler than the air being sucked in.
We know the motor works but has been rewired, we know the fan in top works, we know the compressor works because temp of air is different when O is hooked or not hooked.
So, we have all the major items accounted for. But it appears there is a cooling issue. With O unhooked it goes into heat by default. With O attached it is supposed to cool. With 99 coming out of register shows the air is actually being heated...which leads me to think reverse valve dropped out.
If the R, Y, O is jumped together and the air coming out is warm....we have an issue with either too little freon, or bad reverse valve.
Is it still blowing hot air?