I was hoping to get some help with a frustrating problem with my pool light (and avoid getting electrocuted in the process).
We have a Pentair pool light and niche, circa 1997 or something like that. The light has not been working for a couple of years. This year, I decided I was going to attempt to fix the thing. I replaced the fixture (and conduit back to the j-box), and the ring around the light niche (the pilot screw hole had disintegrated). Put everything back together, turned the light on, and everything worked fine, for about 10 minutes. Then the GFCI tripped. Turned it on again, and the GFCI tripped in another 10 minutes. Subsequent attempts to turn it on led to immediate GFCI tripping.
Without removing it, there does not appear to be water leaking into the light, although it is hard to be sure without pulling it out. After leaving it for about a day, I tried the light switch, and the light went on, to my surprise. I turned it off right away because I was shocking the pool at the time, and didn't want to get electrocuted.
I am wondering what the most likely problem is. Since I found that the ring around the light niche was bad after routing cable through the conduit, I disassembled the light to get the ring over the fixture so I could install it, and then reassembled the light. My thoughts are as follows:
1) The gasket didn't re-seat after I reassembled the light, and the light leaked some water.
2) I messed up the wiring in the j-box, and it is heating up and causing a resistance differential, which is tripping the GFCI.
3) The GFCI has gone bad.
One thing that makes me think 3 is a possibility is that, when I press the test button and the light is off, the GFCI does not trip. I thought it should (not sure if the light switch needs to be in the on position for this to work though). Any help that you could give me would be great. The light is the one part of the pool that freaks me out a little bit. I'm not a big fan of electricity and water.