I have a husky impact wrench, set at 100psi, but all that happens when i squeeze the trigger is air comes out of three vents on the bottom of the wrench, just adjacent to the imput hose. Is there something wrong with the wrench or am i doing something wrong?

There should be an air control valve adjacent to the air inlet, is it opened sufficiently. Failing that there is a problem with the drive motor. It could be seized bearing or a broken vane. There is nothing you can really be doing wrong, it is a very straightforward tool.

Get some air tool oil and put it in the hose connection and manually turn the socket end by hand,the air vanes have frozen in place and can't hold the air in to operate the unit,make sure when you do this squeeze thge trigger to let the oil into the units barrel,then connect to an air supply and try it,you may need to help get it started by hand,then let it run and add some more air tool oil again to keep it lubed