I recently was asked to look at someone's unit they said they had no A/C. i found a tripped breaker. turn it back on n closed the disconect on the unit. compressor doesn't run. this is a 3 ton york. found open whindings. i was wondering if i could replace the york with a new 13 SEER condensing unit with out needing to replace the evaporator. i've heard that the old coil will not match the efficiency of the new condensing unit. also the existing unit is a fixed bore metering device and i believe new units are designed with a TXV in mind. any comments or advice is greatly appreciated. thank you.