Problema con aire acondicionado

[CTScott]

Looking at the Service Manual in regards to the expansion valve, I found the following, which sounds a lot like your problem.

Condition:
Air conditioning system periodically
cools and then fails to cool.

Cause:
Moisture in refrigeration system
freezes at expansion valve orifice,
causing temporary interruption of
cycle. However, when melted, returns to
normal condition

Diagnosis:
Receiver dryer oversaturated
Moisture in refrigeration
system freezes at expansion
valve orifice and blocks
refrigerant circulation