I had a shop rewire my 7 way trailer plug and have no 12volt hot lead now. I don't remember if it was there from the factory? I use it for my cargo trailer lights on my pickup 7 way.
There was no 12v on my '99 plug from the factory, I added it myself to charge the Jeep.
I did the same.
Maybe it's there but they moved it's location.
This should be the standard configuration.
The factory didn't have the standard 7 plug from the factory on mine, it was a much smaller round 6 pin.
And per the original schematics, Foretravel did not wire a 12V charge line to the 6 pin when they built the coach, at least not in 2000 or 2003.
A wire from the back of the alternator had been added to my 7 pin with a fuse. Jim.
The common FT hookup is

Our hookup is also missing the 12V tap that we need to add, where have others grabbed the 12V from? I seem to recall that on our 03 one of the EXTx wires was used from the dash area.
I do like that idea, do you know what value/type of fuse is used?
So going to a seven pin connector made sense to me. I added the electric brake controller wire, main battery charge wire and the handy back up wire from the original spare wires ran from the front of the coach. Seems like I recall a 40 amp circuit breaker similar to the other auto CBs for the charge wire. I had to also add the taillight converter because of the trailer light needs. When I was mounting the seven pin receptacle it seemed like a good time to cut and lift the plate for the plug to reduce dragging. Must take in mine the room needed with the door closed. I hadn't given enough clearance and had to actually drop it down a little. While you're up close please take the time to look closely at the trailer hitch receiver. FT could have done a better job welding them on. Look for signs of fatigue. I line of rust next to a weld, paint cracked in a line following the weld, actual visible crack. Probably is fine but a good visual inspection won't hurt. I've also been adding a switch to power up the trailer back up lights to use as work lights. Real handy at times. Adding power to charge the battery from the Alternator makes good sense because it would electricity separate from the coach when shut down.
Steve looks like 12 gauge with a 30 amp fuse. Has been fine so far. Jim.
For a toad 12 VDC charge line, two good options:
Direct from chassis battery with fuse at the battery. This would charge the toad battery anytime the toad is plugged into the coach outlet.
Use a relay if you only want the charge line hot when the coach engine is running. So, same line from the chassis battery, but use any ignition-hot source in the engine room to close the relay.