Why does the rear AC on my 1996 GMC Suburban not blow cold?

The rear AC in your 1996 GMC Suburban may not be blowing cold due to several reasons, including low refrigerant levels, a malfunctioning compressor, or a clogged cabin air filter. Additionally, leaks in the AC system or issues with the rear AC controls can also prevent proper cooling. It's best to have a professional inspect the system to diagnose and resolve the issue effectively.