A/C questions

[dbl overdrive]

Guys, I'm still learning this stuff about air conditioning so please bear with me. I picked up a charging unit for a real sweet deal and decided to tackle a older N14 truck.The compressor was toast so I replaced that. It also had a ruptured line on high pressure side. I used the 134A and charged it but the compressor would not start.
I used a jumper to the compressor and it took right off.
After I charged the system, I removed the jump and it still won't go. I tested high and low pressure switch and still nothing. A/C blows cold while jumping.
Fuses are good. Is there a thermal switch or somthing?
I still haven't tested the switch on dash eather.
It's a 1990 international. Thanks.