"John Keith" wrote in message
news
Is there a way to test mercury vapor bulbs (with the large mogul
base)? I need to isolate a problem with a large outside yard light and
isolate the issue between the bulb and the photosensor.

Thanks for any tips.


John Keith


No real way you can test the bulb alone, other than to swap with a known
good one, or in another working fixture
But if the photo sensor is the plug and twist type, you can check voltage
there easily enough.

Why aren't you asking about the ballast ?

AMUN