A/C issue
 

91 Accord. A/C will blow cold for 3 or 4 minutes then turns warm. Had system evacuated, refilled/pressure tested. No leaks. converted to r134a in the process. Compressor runs fine. Fans working. Drove for 2 weeks, checked pressure and it is full of freon. Any ideas? Suggestions to check? I'm baffled.

This happens when clutch gap is too large. Also could be a weak AC compressor relay.

Diagnostic for clutch gap is to rap the clutch face w/ a stick. If clutch engages and begins to run, the clutch gap is too large.

If nothing, check whether 12V is being coupled by AC relay to the compressor lead when AC is commanded on and no compressor engagement. If no voltage, then AC relay is faulty.

good luck