It is located on the accumulator/dryer. It should have a black cap on it, and if you buy a recharge kit, the hose will only fit on this connection (it won't fit on the high pressure connector, which is next to the evaporator). This is the only connector used to fill the AC system, even if you have a conversion van with rear ac.
A GMC Savana 1500 is used for several things. A GMC Savana is a large van, so it can be used for transporting large amounts of material to and from places. It is also possible to use it solely for commuting, but that is likely fuel inefficient.
I have a 1999 gmc savana 1500 5.7 and i just replaced my transmission and it was a 4L60E. So yours should be the same.
possibly a clogged catalytic converter
4L60E or 4L80E depending on engine, 1500, 2500, or 3500.
The 2002 GMC Savana has 12 valves.
The 2003 GMC Savana has 12 valves.
The 2004 GMC Savana has a V6 engine.
The 2003 GMC Savana has a V6 engine.
The 2007 GMC Savana has a V8 engine.
The 2011 GMC Savana has a V8 engine.
The 2010 GMC Savana has 16 valves.
The 2009 GMC Savana has 16 valves.