Auto Air Conditioning & Heater Repair: air cond, chev tahoe, psi performance

Question
1999 chev tahoe with dual air front air blows outside air rear air blows cold

Answer
I THINK YOU QUESTION IS THE FRONT A/C IS NOT COLD COMPAIRED TO THE REAR UNIT. FIRST,CHECK THE ACCUMULATOR AT THE ENGINE FIREWALL-RIGHTREAR CORNER - SEE IF IT`S COLD.IF IT IS, YOU HAVE A CONTROL DOOR PROBLEM IN THE DASH.IF NOT,THERE MAY BE A BLOCKAGE OR LACK OF FREON IN THE SYSTEM. YOU NEED TO GET PRESSURE READINGS WITH A SERVICE GAUGE TO CHECK THE PSI. PERFORMANCE OF THE LOW AND HIGH READINGS FIRST.IT`S GUESS WORK WITHOUT THAT.

GOOD LUCK,DAVIDT