Same thing happened to my RW. There are two little metal tabs sticking out of the ports in the back of the light. Hard to see, got to get in there.
My tab was not centered so when I plugged in the "female" end of the wire, the tab slipped above it not into the slot.
Got some needle nosed pliers and carefully straightened out the tab. Then pushed the connector it nice ans snug. Worked perfect.
This is how I got it from the Rad Power store in Seattle. They insisted it was tested and in perfect condition when I bought it. First thing when I got it home was tested the lights. Fail. Called the tech, he seemed confused about a few things but mostly walked me through it.
I would love to find a more powerful light that uses the same hook up. I use it as a day time running light but if you ride at night you will need lumens..... Lots and lots of lumens.
Try checking the metal tab. It worked for me.
