By pin out do you mean what wires coming off the relays power the power supply functions?
There were a lot of versions of the relay powered bars. In general, the power supplies were not that much different than other edge bars. So essentially you have normal edge power supplies getting "high amp power" from the bar in one lead and switching power in others from the relays. You can trace them back pretty easily. I don't know of any actual diagrams of pin outs for the internals of the bars. I will dig through my stuff and see if I have a generic one that comes close.
You can try google searching with the qualifier "site:https://www.whelen-engineering.com/" that is where the older install guides are stored. Some of the contents are below. Granted I still didn't find your specific bar I don't think.
Official site for Whelen Engineering. Designers and manufacturers of emergency warning and lighting equipment for Police, Fire, EMS, and DT professionals worldwide. All products Manufactured in America