I have a 2004 Suburban 1500 5.3 . My problem is my ac and heat works perfectly in the back but the front doesn’t have any temperature it juss blows air

 

Could be low R134a due to a leak, and common for front to be warmer under that condition. Go to an independent mechanic or specialized AC shop to get leak diagnosed and fixed, and the proper amount of R134a by weight replenished.

But if heat and AC don't work for the front, sounds like one of the electric actuators under the dash. I replaced one of those on my 2005.

 

if you have cold air in the back the refrigerant level is probably ok as both front and rear systems are connected. Having both no heat or cold...I would check the blend door actuator.

In the front system, all air that comes into the hvac box goes thru the evaporator. the temp blend door actuator moves a door in the hvac case to either allow air flow from the heater core or bypass heat from the heater core. their are 3 or 4 actuators depending on the system design
- recirculation for where the source air is drawn from...in cab or outside air
-mode door for which vent it blows out of
-1 or 2 temp blend doors for hot or cold air....dual climate systems have 2 single zone have 1

find the temp door actuator and see if its moving when you change the temp setting.

 

The high pressure side of the AC splits into two paths: the front evaporator is supplied through an orifice tube, and the rear through an expansion valve.

 

if the system works at the back...the refrigerant level can't be low only in the front.

 

Not completely true. My 99 TAHOE the rear Ac worked fine EVEN though it WAS low on refrigerant. The problem that caused the leak were the pins/valves on the high/low fill valves.

 

what he is saying if the system is low it wont trip the pressure sensors and the compressor wont kick on. if the compressor kicks on then the system can be on the low side but not low, you will still get cool air out both if the blender doors are working right

 

if the system has enough charge to work in the back...it will work in the front. 1 compressor supplies the pressure for both front and rear.