Lighting, Light Fixtures, Ceiling and Exhaust Fans - off and on

I have a mercury vapor dusk to dawn light that cycles on and off. The guy at Lowes said that it is the eye 90% of the time. I replaced the eye and it's not fixed. Are there any other replaceable parts in this light? Does anyone have any ideas as to the problem?

Thanks
Gerald

Check the ballast or the bulb.

The most common cause of "strobing" with HID lights are:

Wrong bulb for orientation. Yes the direction that the screw shell points matters.

Wrong lamp for the fixture. Make sure that the mfg matched them.

Ballast at end of life. Replace it and all the other components at the same time, if this is the problem.

Light fixture shines on photo eye. Think of how long it takes this type of light to start and you can realize that if the light points at the photo eye, it will turn itself on and off.

Check out this link.
http://www.advancetransformer.com/uploads/resources/hid-troubleshooting-guide.pdf

More good references are available up one level at the same site:
http://www.advancetransformer.com/resources/literature.jsp

Very good light.
As stated, Check the location of the P-cell.

I have an outdoor light (not mercury vapor though) that I had a similar problem with. My problem turned out (I won't go into the details of how I figured it out) to be because of the location of the light. It was too close to the overhanging top point of the roof. I surmise that the light from the light itself was being reflected back to the light's sensor. I moved the light fixture down about two feet on the outside wall and this resolved the problem.

Hope this helps...