Discharge Resistors

One problem with using capacitors in light ballast designs is that the capacitor tends to carry a charge even when the circuit is off.

This is a problem to whoever services the light since the current carried in a capacitor can injure or even electrocute. To prevent this, most ballast manufacturers add a discharge resistor across the terminals of the cap to safely discharge the current.

However some capacitors don't have this and most aftermarket caps don't have them either. Adding one is pretty easy, you just need a resistor that can discharge the current (I used a beefy 1.8M ohm 2W one) and a soldering iron to solder the resistor on the cap.