2003 kia van rear air blowing hot

If the heater hoses for the front heater are getting hot, it could be a blend door problem under the dash.

First I would check your radiator fluid level, sometimes being low can have this effect. Usually the rear heaters sit at a lower level and so keep working. If that is fine, then you probably have an issue with the diversion door or controller that controls the hot/cold mixture.

first i need to no if yours is all factory air then i can help more about your question thanks i want to give a answer on the problem when your ac unit gets gold in your dashboard but not in the back is you will need to add more Freon but not a lot and watch your pressures I think that will answer to your problem

on most tahoe and yukon its only rear air and not rear heat my 99 yukon has only rear air

I had the same problem with sebring 2003. n the solution that i got was to top up the radiator colant.
hope it works for u too.

often on the vans with rear air the air dor acuator goed bad and can no longer switch from hot to cold. also the swich itself will often go bad. this can be caused by sticky fingers damaging the inside of the switch. sometimes a good cleaning in warm water will fix a sticky switch

More than likely this is the rear orifice tube(or rear metering block) same concept.This invloves evacuating the ac and removing the orifice tube and repl;acing it.This is just normal maint that is accustomed to this vehicle.Please get back to me with any more questions...thanks!!!

Try this article. I have the same problem and I think it is the vacuum motor that controls the door for changing from hot/cold in the rear heater box (located inside behind the L rear wheel)

https://www.fleet.ford.com/truckbbas/non-html/Q19.PDF

Temp. actuator maybe. A electrica motor that moves a door from cold to hot in the rear HVAC unit . Removing the rear trim panel to get at the auxiliary HVAC unit would need to be done . Search on youtube , video showing how to do it .
Rear auxiliary heat and actuator overview repair for Yukon Tahoe Suburban...
2004 Tahoe rear hvac system only blows cold air diagnosis and temporary fix