Hello, the university that i do electrical maintenance for, has a handful of stadium light bulbs that arent working. These are metal halide bulbs, we have replacement ballast on hand, i just had the question. Is there anyway to test the existing ballast to make sure im not replacing a good ballast? Each pole has 20 or more lights on them with individual ballast. Is there a quick way to find which ballast goes to which light? Ill attach a picture of the new ballast, unfortunately most of the troubleshooting to get to this point, of deciding its a ballast, was done before i started working here.