Alternators have replaced dynamos as generators on todays modern cars. One of the key benefits is that they can produce more current. Any short or open circuit, as well as wrong connection can cause a sudden surge of voltage that will damage electronic parts, especially the Car Battery. Checking alternator output using an amp meter in series with the charging system should be done only by an Car Battery Specialist. You can do a safe test with an induction amp meter held parallel to the output cable, but it is less reliable and we would recommend to drive through to your closest Battery Clinic store for us to assist you with the correct equipment. . It is advised that you also check your alternators charging ability at least every 6 month and your local Battery Blinic will gladly assist you in this matter.