I need to help him fix this since it keeps hitting 110 in tx.
Well, without seeing how your vehicle is plumbed, I can tell you that a lot of rear air conditioners in van-sized vehicles have their own separate air conditioner rather than using the front air. It’s often found in a little box in the very back of the van, on one of the sidewalls down near the floor. That could explain things - the front air conditioner is broken, but the rear air is not. As to why your front air isn’t working, the most likely reason is that the refrigerant needs to be recharged. Be aware that the reason it needs to be recharged is likely because there’s a leak, so you might want to have the AC shop include tracer dye in the recharge so that if it leaks out again, they can look for the dye and find the leak.
If the rear AC is cold it means the system still has enough refrigerant as the front and rear AC use the same compressor. If the front is emitting hot air instead of cold air then more than likely there’s a problem with the front ventilation system. Such as a blend door failing to go to the proper position to provide cold air to the front.