95 geo tracker a/c problems

i dont see whats wrong
it blows but thats all it does
i dont think the little thing that holds the freon is turning on
it depends if its a cold day
itll blow cold
and if its a hot day ill blow HOT HOT

is there a fuse or something thats missing
can anyone send me the electrical system of the a/c?
i recharged it too but that didnt help
any suggestions?
everything looks connected except
in front of the radiator
in that little spot
theres like a black little plug about this size ( )
just sitting there?
does that go anywere?

You need to get an AC pressure gauge to see if it's charged to the right pressure, about 50-55 on the low side. DON'T overcharge it. If it's charged right, then you'll know for sure to look at other things. Ed

You need to get an AC pressure gauge to see if it's charged to the right pressure, about 50-55 on the low side. DON'T overcharge it. If it's charged right, then you'll know for sure to look at other things. Ed
thats exactly what i did
i bought a a/c recharger with a gauge
and it was in the blue section
so i filled it up to the green

and it still didnt work
even as it was going in it the pipe was cold but it wasnt coming out cold