I assume you've followed the instructions in the manual for the rear air conditioning? Note that the temperature from the third row vents can only be the same or colder than the temperature set in the front. When the rear A/C is on it will only cool the rear not heat it. Thanks for replying, my problem is i cant get any heat into 2nd and 3rd row vents at all, front is fine , 2nd row you can hardly feel any thing, and when i switch the 3rd row on its just cold air and plenty of it,- should the heat be the same from 2nd and 3rd rows as the front temp, i dont get anything, only heat from front.( dont have a/c on at all , just want heat in the back )