<<or is this a situation where there's enough pressure for compressor engagement but not the Aux Fans (meaning fan resistor might be suspect).
There are 2 switches , one for compressor and one for low fan [a/c].
The first sign of slightly low freon is no low fan..
If fan comes on with the leads to the fan pressure sw jumpered,
the resistor and electrical integrity of circuit is fine.
If that works, then you are prob. not getting to cut-in spec of the switch [20bar]
due to low freon.
See other post from today...