I have a RPJ2 (mod/ser above) without a wiring diagram. Apparently there have been some VERY creative individuals that have worked on it over the years.
Last tech did something that by-passed off/on then left for parts unknown. New tech said that it's a good unit, but the wiring is a mess and there's no diagram. And without the diagram, he can't put all the pretty little wires back where they belong.
Even if you had a wiring diagram that would not mean the original components are being used therefore the original diagram might help a little but if some creative wiring has been done since its inception the diagram won't do much good. That B number looks like a goodman number. I have no idea what an RPJ2 is. What are we trying to wire?
____________________ "May the hinges of our friendship never grow rusty"
-old Irish saying
Look in the yellow pages for your area and find the local Carrier distributor (Comfortmaker is a sub product of Carrier Corp).
Call the parts counter and give them the model serial number and ask them to send you a PDF copy of the diagram to your personal email address.
There shouldn't be much for a seasoned tech (motor speed taps, safety switches, and gas valve circuit). If it is circuit board driven then all one needs to do is look at the board terminals and hook up the circuits one by one - they are all labeled on the board.
If it is old school relay driven then a good tech who understands Order of Operations should be able to noodle it out reasonably quick.