A/C only blows cold in rear, front blows abient temp. on 1994 GMC Suburban 1500

I have recharged the A/C system, however the front still will not blow cold air. Any thoughts?

Asked by for the 1994 GMC Suburban 1500
TRy the relay switches( there are 4) located behind glove box. The rear has its own switches, that is why it is not affected.
Thanks for the help I switched them around and it is now working!