2007 Acura TL AC works intermittently

A/C works intermittently. works good in the morning when its somewhat cool 75 deg then blows hot when temp rises. ac clutch wont engage, tried clutch relay had same problem. even when temp is 100 plus it cools for about 10 min then blows hot??? Honda wants 1800 for new compressor. ac works great when ac clutch engages. fully charged im at a loss??? Ran air temp sensor test came up E9 could this be it?