I have a 98 FordEscort ZX2. I'm having trouble with the A/C not working properly. It seems to work fine when Ifirststart the engine as long as the engine is cold. But once it reaches operating temperature after about 10 minutes it shuts down and starts blowing warm air.I can't seem to figure out why it starts out working then stops once the engine warms up. Any ideas would be a help.

Thanks

 

You will need a Refrigeration Manifold Gauge Set to properly diagnose your system. We will use 30 psig on the low side and 180 psig on the high side as a norm for the purposes of this discussion
Note: An adequate quantity of refrigerant is assumed.
INTERPRETATION OF GAUGE READINGS

Below find a list of possible gauge readings and what they mean.
High low side and lowhigh side readings. Your compressor is bad. The closer together the readings are, the less efficient the compressor is.
Low side into vacuum, high side normal. Expansion valve stuck in closed position, clogged with debris or restriction in the liquid line.
High low side, normal high side. Expansion valve stuck open. Hot water valve (heater control valve) trickling hot water into heater core causing AC plenum to get warm. Open seam on evaporator case drawing hot air from engine compartment. Bad condenser fan. Bad fan clutch. Too much oil in system. Possible overcharge and what appears to be a normal high side is actually too high.
Highlow side, high high side. Overcharge. Dirty condenser fins. Problems with cooling system, condenser fan(s), or radiator fan clutch. Restriction in condenser. Clogged drier.
Normal low side, high high side. Restriction in condenser. Overcharge. Clogged drier.