Air conditioner vents in back seats aren't blowing.

There's no air vents for back seats. Air only blows for front seats. the vents you see on the bottom of the back bench are actually vents for the hybrid battery.

 

IF.....there really ARE vents in the back, they likely produce air ONLY when the controls are directed to the FLOOR in front.
And the dogs would not be a factor unless they got under the seats and chewed up the ducts.

The combination of the replies you already got contain the answer to your question.
Your guess is WRONG.

 

Cooling performance of the HV battery not AC and air doesn't come out of those vents, it's sucked in by the fan shown in the video, no relation to the AC at all.

 

None of them are directly tied to the A/C system. All of them are indirectly tied to the A/C system, by being in the same car.

Those vents under the rear seat are there to pull air conditioned air that is floating free in your cabin and draw it through the traction battery. There is no direct airway between the air conditioner and the battery, all that air passes through the open cabin along the way.

It is still a good idea to verify that the traction batery cooling fan is operating normally- it's just that you'll never feel cold air coming out of those vents on the rear seat because that's not how they work.

 

FWIW, the filter in those vents could become blocked with dog hair. If you get any HV battery warnings it's worth checking they're not blocked.

 

MY 2020 LE has a switch on the right side of the climate control panel that changes the AC to front only or front and back. The vents for the rear are under the front seats facing rearward.

 

I The button just prioritize air to the driver's vents. interesting, I wasnt aware there are vents under the front setas blowing at rear passangers, I have to checl=k.

 

I guess I need to do some experimentation since I never sit in back. If S-Flow mode prioritizes AC to the front and there are no A/C ducts to the back, how does it work when not in S-Flow?

 

It is possible to select A/C and also select floor outlets. If you do that, hey presto, you do have "rear A/C", and you can gaslight your back seat passengers and say you have no idea why their toes are chilly.

 

I recall seeing rear ducts under the front seats in the Gen 3, but can't see any in the Gen 4.

 

Cold? Heater? Whazzat??

Prime has ducts under front seats, but you have to stand on your head to see them.

I suspected that and was going to try it. Not sure how it would affect S-Flow. I do know it will turn off the "Auto" indicator.