The air conditioner's clutch air gap is causing the compressor to engage and disengage, so it cools sometimes, and sometimes it does not. If the clutch is pushed in, then the compressor engages and starts cooling.
There are a few things that cause the compressor to cycle; the clutch is not usually one of them. They typically work, or do not work. You can backfeed a test light into the circuit to see if it is reacting the way it should. It sounds like you have a biased cycling switch, or a low charge. The only way to know for sure is to have the AC system inspected. Consider YourMechanic for the inspection and repair - our mechanics provide diagnostics at your home or office.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing