Welcome PleinairGal...
There are definitely variations between years and models on location of fresh water tank, pump, water heater, etc. Not sure exactly which fitting he is looking for.
On my 2014 Hurricane - the fresh water tank, pump, city water connection are all visible under the bathroom sink or from cabinet on opposite side of wall... The hot water heater is under the kitchen sink.
Best to contact Thor directly and request the specific plumbing drawings for your rig (by VIN). MIght as well ask for the electrical at the same time.
You can start here online:
https://thormotorcoach.com/customer-care/
Page also lists a phone number if you prefer.