Last Thursday night, we had heavy wet snow followed by rain. I was out in the weather, making an airport run, during the snow. When I came home, I plugged in to my 2nd generation HPWC, as usual. In the morning when I unplugged, the light around the charge port was red. Never had seen that before. Charged the car at a nearby Supercharger to make sure it wasn't the car. Came back, and tried plugging in again, and everything looked normal, got a blue ring. Charged some at home, all OK.
Yesterday (Sunday), the ring lighted up red again. I unplugged and used the reset button on the Wall Connector. Light on WC turned green. I plugged in, and charged for a while in the afternoon. Weather was dry. Went out to dinner, came back, plugged in, got the red ring again. But after unplugging and resetting 3 or 4 times, it looked OK, and it charged successfully overnight.
Today it is raining very lightly. I got the light again, this time on the WC itself while the charging cable was not plugged into the car. Tried repeatedly to reset the WC, and it would not reset.
According to the trouble-shooting guide, this indicates a hardware failure. Several specific possible failures are listed, and the suggested solution is to "Call Tesla." I have placed a call to the home charging support line, but have not yet reached anyone. (Left a message.)
I think the fact that the red light is on without the car plugged in means the failure is not in the car. Too bad in a way, because the car is in warranty, the WC is not. Plus, it will be a headache to uninstall the WC if that is what Tesla tells me to do (assuming I ever reach someone). Even though these incidents seem related to moisture, I have to wonder why none of the specific codes related to moisture have been displayed.
The WC has never displayed anything except green until now, never needed a reset, in about 26 months of use.
