Pretty sure that would do nothing useful. A diode is the electrical equivalent of a one way valve, so you either bypass the ballast all the time or you never bypass it, depending on how you install it. In the factory setup the ballast is bypassed in crank mode in order to give full voltage to the coil and allow it to fire. The reason for this is that during cranking system voltage drops and if you fed it thru the ballast as well the coil might not be able to make a sufficient spark.