This year and last year I started having problems when it rains, causing my Christmas lights to go out, tripping the GFCI.

The GFCI plug is located in the garage, and has all the outdoor covered outlets running through it. The circuit is 20 amps, and I'm running 14 amps of minature outdoor rated lights. There are no frays in the wire and every wire receptable/connection is wrapped with weather proof electrical tape and plastic. I'm using all outdoor extension cords and everything is controlled from 3 heavy duty outdoor timer outlets with covers. I additionally covered the timers with plastic bagging. The timers are connected to the outdoor receptacles on the house, which have plastic bubble cover plates.

I'm stumped as to why everytime it rains, the GFCI trips. Should I lower the amps going to this circuit and divert to another plug on another circuit?

I do have one set of lighting on the left side of the house (about 4 amps worth) that runs to GFCI plug in the house that is on a different circuit breaker. This seems to have no problem when it rains. I'm wondering if I should take about 4 amps off the larger load and add on to this other circuit.

Any suggestions?

Lowering the load should not affect the GFI receptacle trip other than you might be removing whatever piece of wiring that is causing the problem.

You might try spraying some WD-40 into the ends of the extension cords and on the plug end of each light stringer. Or, wait until it rains again and unplug 1/2 of the lights, this will narrow down your search. Once you determine which 1/2 is causing the trouble, divide that bunch in 1/2 again until you finally find the culprit.


Finding GFI problems can be a frustrating experience.

Thanks for the information! I'll see if I can figure out. They are all new light sets.

I did reduce the load so I have about 8 amps on two different circuits and GFCIs. Could it also be that the one GFCI receptacle is bad? The other seems to work fine with the lights int the rain. Of course, this only one half of the lighting. I guess the problem could be with some light set or cord on the other receptacle.

"Could it also be that the one GFCI receptacle is bad? The other seems to work fine with the lights int the rain."

Easy way to tell is to switch the receptacles those loads are plugged into. If then the other GFCI receptacle starts tripping, then the problem is somewhere in that set of lights & extension cords. If the same GFCI receptacle still trips with a different load on it, the problem is indeed likely in that receptacle. (But it may just be that this one GFCI is more sensitive to a ground fault and trips faster. That's not really a 'problem'; we want GFCI's to trip fast, before a human can sense the shock.)