Dead Fan... check the FUSE before proceeding.
If you install the wiring wrong, the fuse will blow immediately. Reverse the wire polarity.
Your fan is similar, if not the same, as mine in the 2006 Safari 23 foot. Noisy, as well.
Next is the Snap Switch. When the ammonia lines heat up, the switch SNAPS internally for power ON. When the coils cool... OFF. Jackson Center sent me one when mine went bad. It did not work either, ordered one on EBay that did work. P.o.S. I say.
Amateur test of Snap Switch: Put a lighter to it, heat it up. Fan starts... good. Fan does not start... fan could be bad or a bad fuse. Snap Switches are problematic.
Find the Snap switch. If you have a voltage tester that checks Open or Closed... that would help. Same with the fuse, if you find it. Look to see if it is good. If not you will likely see a black carbon spot in the center, or the center missing/melted.
Snap switch should be touching the ammonia line to get heat off of it. If not touching... wire it to the larger tubing to get maximum heat to function. (another test you can do)
I fought with this thing in the 2006 23 footer that had the Microwave, so you need the fan. Without the microwave... the refrigerator vents from the roof. First thing I looked for in the 25 and our current 27 foot. No fan... no problems, ever again.
Good luck. I still test 9 volt batteries using my tongue to measure voltage. If this helps, great. Get use to it. I am incompetent, but my polarity is excellent. I wired my 100watt Costco Solar Panel to my batteries and... it works.
Fuse. Snap Switch. Fan.