The expansion valve (or metering device) on a 1993 Chevrolet Suburban's A/C system isn't in a single, easily accessible location like a large valve. Instead, it's integrated into the
A/C evaporator. The evaporator itself is located
behind the dashboard, within the HVAC system.
You won't be able to access or work on it without significant disassembly of the dashboard and HVAC components. It's not a part typically serviced individually; if the expansion valve/metering device is faulty, the entire evaporator assembly is usually replaced.
