[particlewave]

For $20, you can't really go wrong with a refill/gauge kit. It will give you a better idea of what's going on. Most likely, its just low. Do your research and make sure the refrigerant is compatible with the existing system and any remaining refrigerant. Get a kit with sealer as you probably have a leak.

If it works for a while, then quits, take it in for servicing. This would indicate that the leak is more severe. If the refrigerant is not low, or adding doesn't make the compressor kick on, then you have a compressor failure or electrical issues.