Alan-
According to the "Front End Wiring Installation" diagram (link
here, Sheet 8 (page 9 of the PDF document)), the temperature sensor is attached to the front grille. Four styles of grille are shown on Sheets 7 and 8. Sheet 7 is for Winnebago, and Sheet 8 is for Itasca. Your model of Itasca is a "G," so your grille should look like the one on the bottom of Sheet 8 (again, page 9 of the PDF document, i.e., its last page).
All the diagrams for your coach are available at
this link.