Greg, that would be right up your alley. Fabricate a jig to hold the compressors, rig up an electric motor at approx 1750 rpm, a 12 volt battery with the right connector and a switch to engage the clutch, a cut-off rear connector with a Milton air chuck soldered to it for a pressure gauge to connect to, some oil to put in it to run it, and fire it up. You'll be able to check the output pressure and if you rig up a ball valve you'll be able to check the compressor for leaks with some soapy water. You will also be able to check the clutch engagement. However, the time and money put in to the fabrication would probably be better off spent on a new or rebuilt compressor. Your time is money!!

__________________
Orland Park, IL
1985 300SD 215,000 miles