Curious if anyone has the Barth and/or GM wiring diagram for the Aux start + Cole Hersee continuous duty solenoid setup, and could upload it?

Looks like a PO installed a big blue Napa 3 post diode style isolated and disconnected the aux start switch. The solenoid above the alternator seems to be bad (continuity between terminals that shouldn’t have continuity I believe) but still has power to it, so I’m a bit confused as to how it’s supposed to be connected. Logic would tell me the aux start switch just Y’s into the 12v engine on feed to the solenoid, I assume with 12v from the house batteries, so it can be activated with the engine off to start the motor with a dead chassis battery. But really I’m just guessing. I’ve seen some talk that this solenoid is actually a GM outfit from the factory and is simply a remote solenoid for the starter, but I don’t have another aux start solenoid that I can see.

Any insight would be appreciated.