Norcold Refrigerator Exhaust Fan Kit

1. Yes, the fan kit removes the hot air, drawing it from under the cabinet and exhausting it through the vent. My A/C actually ran less during the 90*+ days last week after the fan kit was installed.

2. Yes, my fridge is now a constant 32*, not 37* to 42*, and I was in the process of dialing it in to be about 33*.  This means the fridge compressor should be running less. 

3. Use it during hot weather or whenever the counter is too warm.  The hot air will be appreciated during the cooler months.  Use it all of the time when the extra heat is uncomfortable.  There is an on/off switch that is placed above the fridge so it can be turned off as needed.  Add the step to turn it off when towing, if you normally turn the fridge off when towing your T@B.

4. The A/C 12V assist fan is only used when you use the A/C.  The fan removes the hot air from the A/C cabinet and exhausts it out the roof vent (at least that's the way mine is).

Please install it.  Your T@B is under warranty and you do want to make sure your fridge is working properly while under warranty. 

Tweedrvr - Not surprising you haven't heard about it, it's a 2-week old mod.
If you have the 3-way fridge internally, this would apply to you. That fridge has a vent hole in the floor for incoming air and an exhaust vent out the passenger side forward of the door. Without the kit, heat builds up too much under the counter top. This kit draws this fridge heat out thru that side vent. The factory is installing it on all new T@Bs coming off the line and it's a free kit to current owners. You can have your dealer get it and install it or you can call the factory (ask for the fridge fan kit) and get it yourself.

Sorry, Verna.  Meant to respond to PXLated.  Having case of humidity in the brain housing unit!

Frankonsand A lot of us have installed aftermarket fan kits that attach to the exhaust vent by the door and power them off the 12v connections under the stove. Here's mine.