On a generic print i have, prp is fed from terminal LCS which is hot side of the line, through FP contact, then through the ACO and DCO which are ac overload, and dc overload contacts, then through a AUX1 and AUX2 contacts which note says will be open if circuit breaker is tripped. then to prp terminal. the Prp terminal then goes to the GEN output circuit which if cpu is turning on, will pick up GEN relay, then from prp terminal we come through a normally open GEN relay contact that then goes to the y+d starter coils. need to check to see if you have voltage from LCS to LCO. If you are good there, then you are open on one of the below terminal points, FP terminal for fp contact, OVL terminal for overloads, and CBK terminal for circuit breaker aux contacts

when you say you try jumping prp, where are you jumping from? LCO is the common, so you should have 120 vac at the above terminal points, if not that circuit is open. if you have voltage at prp, then you are open farther down the safety circuit. i have some generic prints, pm me your email and i will send them to you