2004 Tahoe A/C problem

2004 Tahoe,actually two intterminted problem, but may be related. The vehicle has dual temperature controls on the dash with digital reading. The a/c cools fine on driver and passenger sides when temp setting is set below 67 degrees, but blows warm just on the passenger side if temp is set at 67 or above. The driver side continues to stay cool at the desired temp.
The other problem is when idling,the a/c will shut itself off and the temp screen with the temp controls on the dash goes blank. You actually have to push the ON button and the a/c and digital reading comes back on. The dual thermostat control unit in the dash has been replaced and did not solve the problem. The rear a/c is not affected, the temp controls are on the ceiling.Sometimes there a gurling sound coming from the fan housing, but may be the heater core.Again, this is a come and go issue,not all the time.Any ideas would be greatly appreciated.

this is the auto a/c system..since its shutting off randomly I would check for fuses loose/power to the a/c computer..if all is good replace the a/c[computer] control unit.