2003 S10 a/c problems?

I have a 2003 S10 pickup 4.3 V6, the low pressure switch was unplugged, when i plugged it in the compressor kicks on the right back off. When i bypass the switch the compressor stays on but air isn't blowing any cooler. Checked the freon level, high side is showing normal, low side is near pegged out. No change while compressor is running. Any suggestions?