So not a wiring diagram, but found a video where they go over the installation of the OEM Trail Hunter tire inflator (PT949-35240) using that connection.
Info you might be seeking is at the 14:20 mark. Hope it helps.
So, I recently used my '24 PrerRunner to tow my GR from NorCal to Arkansas, which was roughly 1800ish miles. When I went to reserve online it initially didn't allow me just like you described, but once I went in person they authorized it. The total weight was roughly 5.5k lbs (3.3k car + 2.2k...