Chevrolet Repair: 93 Chevy mystery, throttle plate, c comp

Question
I have a 1993 chevy Z71.  I can't begin to tell you the parts we have replaced.  The issue is when AC is on, truck in gear, you turn steering wheel and truck cuts off.  This primarily happens at idle.  It's like the truck idle is too low.

Answer
THIS SOUNDS LIKE THE A/C HIGH PRESSURE CUT OFF SWITCH ON THE POWER STEERING LINE HAS FAILED. JUST A GUESS,BUT WHAT IS SUPPOSE TO HAPPEN IS WHEN THE STEERING WHEEL IS TURNED OR TURNING AND THE A/C IS ON,, THIS SWITCH CUTS OFF THE A/C COMPRESSOR TO LESSIN THE LOAD OF THE ENGINE SO IT WILL NOT STALL, OR IT WILL RAISE THE IDLE SPPED. IT SENSES HIGH PRESSURE IN THE POWER STEERING SYSTEM AND LIKE I SAID CUTS OFF THE A/C..SO IF THIS SWITCH IS BAD  AND DOES NOT CUT OFF THE A/C COMP THIS WILL LOWER THE IDLE TO POINT OF STALL..THE SWITCH IS ONLY ABOUT $23.00 OR SO...I WILL ASSUME THIS NEVER HAPPENS WHEN THE A/C IS OFF. IF IT STILL STALLS, THEN THE ABOVE IS NOT OUR PROBLEM..NOW YOU MAY HAVE A BAD TPS OR IAC OR THERE IS EXCESSIVE AMOUNT OF CARBON BUILT UP ON THE BACK SIDE OF THE THROTTLE PLATE..CK IT AND CLEAN IT, IF NEED BE.. SORRY ====IAC[IDLE AIR CONTROLLER] TPS [THROTTLE POSISTIONING SENSOR] GET BACK TO ME IF NEEDED,HOPE THIS HELPS YOU,,,TOM..