There is only one way you can "check the A/C level", and that is to recover the freon, pull a vac, and then add freon by weight.....
You said the pressures were checked....what were the low and high sides doing?
This is a CCOT system, so the compressor will shut off and cycle......
You say, when the compressor goes off, it stays off, but if you jumper the harness to the low pressure switch on the accumulator, it comes on?
Since you replaced the switch, you need to have gages on this when the compressor cuts out......see if that low side is going well below 30psi......