i ahve a 96 ek compressor good,new belt,new pressure switch and condensor, has good refrigerent but only cool in the middle vents and when i cahnge the location to where i want the air to blow i gets warm losing its cool and doesnt really blow cool. cahnged the cliamte control too. someone told me it could be a the evaporator bad waht do yall thing n has new lines too

 

a bad evaporator will cause poor cooling overall, not sporadic, if you have the **** type climate adjustment (with three *****) the duct gates might be broken, loose, ir disconnected, which can happen over time.

another thing, does the compressor have oil in it? if the oil level is low, or there is none, it will cause the compressor to freeze more quickly, making the A/C system cool intermittently.

those are suggestions, the first place i would look is the gates, can check the heater hose linkage under the hood, its got a cable running to it, and it can get stuck sometimes, causing the air to heat up. i might suggest starting with the base of the problem, what work was done, anything broken or possibly hooked up wrong?