ab, I have been researching how my '94 Monaco Destiny,
with an Allison MD3060, is currently wired with an aftermarket installed PacBrake. I have consulted both Allison and PacBrake and have located what appears to be the factory installation instructions for my situation. The following link lists engine & transmission combinations and the points to PDF files with installation instructions.
Cat c7 engine brake, Jake Brakes, exhaust systems - Installation procedures and Schematics
In my case
I think the following link describes how the PacBrake should have been wired to the transmission push button control head (VIW) and the (VIM) which is the 7"x7" black relay box interface module that is located in the front run plate panel.
http://www.pacbrake.com/PDF/L5114.PDF
I hope this info is of help. PM me with any question you may have,
Larry