Ac compressor won't come on

MUST be checked with a set of manifold gauges,no other way,low side and hi side! A/C Pro's love the summer when folks go and buy that can from Walmart or a Parts Store. same with home A/C,must check with the same gauges,more factors play into this,but I know,we just want it to blow cold cause it's 100 plus in most places now,A/C spoiled us,but hey I love it too!....