2011 Ranger AC clutch cycling on and off every 3 seconds and won't accept 134a charge.

As I mentioned in the subject title, the clutch is cycling on and off every 3-5 seconds. This is normally a low charge condition; however, when I tried to add charge it wouldn't accept it. I used several different can taps so I doubt this is the problem. This truck has a low pressure switch and a high switch from what I gather either can cause this cycling condition.
To me it seems like the system is blocked somewhere. My question is does the low pressure switch block the flow or is it just a sensor? Any one have experience with this this?