Light switch is on. Lol. My problem is intermittent & it just so happened to start when I plugged my clock back in. So it was a shot in the dark. I have noticed now that there is a humming sound coming from behind my dash & I seem to only hear it sometimes when I cut my car off & sometimes when I cut the car on. It doesn't do it every time. I opened my door today & sat down & saw that one of the LEDs in my gauge cluster was lit up & I heard the humming noise behind the dash. I didn't have the key in the ignition or anything in the car turned on. So that was very strange. I just sat there & the LED went off & as soon as it did, the humming noise stopped. I don't know how these after market LEDs in my gauges work because they were installed previously before I bought the car. Can somebody who's messed with them before tell me how they work? I have a feeling that whatever is making this humming noise may be the culprit.