Been using the Unilite's since 1981 and have never lost a light. Have one in my current car. Been in there since 2002.

The ONLY two ways to kill the photocell is to jump start the car with the dizzy plugged in, or to try and start a dead battery with a battery charger. You can buy a $40.00 filter as well.

They are virtually bullet proof, but evidently not idiot proof as many have killed their photocells doing exactly what Mallory has said not to do since the Unilite was intorduced.