Question about A/C system on Ford Explorer?

2000 Ford Explorer with the 4.0 and automatic transmission. 140,000 miles. Okay, sometimes the A/C works, and sometimes it doesn't. It first started getting finicky when going down the highway. Acceleration from 40-55 or so would completely kill the A/C system as in it would still blow air but it would be warm. Now it's staring to blow warm air at random. Most of the time it's still cold but just has hick ups where it's warm. When it's cold though, it's cold. I'm having a debate with her stupid uncle because he's saying the system needs to be recharged. I say NO! It's the compressor or the clutch that's going bad. Big Best Answer going out with this one fellas.