This valid, I have an 03 Elantra GT and the lights were staying on without key etc.. Sometimes the car wouldn't start, sometimes driving down the road the lights begin to flicker, or one of the more amusing ones, the doorbell dings and the car immediately kills n goes black. maybe everything shuts off and turn back on real quick. all these things checked as shorts, g-faults, n relays as they were, but jobbed separate.Just started having this problem last two days. Think for me its a relay/sensor related to the brake pedal. I depressed the brake pedal all the way and pulled back against it (towards me) and the light went out. See if that works until I find out more about this.
Kind of a forest not the tree should POV should have been taken. I had no clue other than how to fix it every time till the next supernatural event. I'd try to pick each thing and I lose my mind, well after God knows how many days and hours of painstaking research and just complete car **** I had discovered Bass cause my problem, other than the relays sticking, wires shorting, batteries draining, starter's not starting, I have had Crazy Ants open my wiring especially in my ECU n fuse boxes in and out,
I bought some furny safe bug bombs n QD contact cleaner. Bombed then flushed all that bug crap out, most looked ok at a glance, but relays boxes once open i was fairly POed. The guys are corrosive and conductive. Then serious chemical warfare ensued, but also why i took this approach was because this point I did not want to add to the money pit when obviously i I was combating some kind of swamp bug voodoo.
So when I got checking out the electrical components, components I would just get some small tools, that contact cleaner clean everything pristine. any stragglers can lead to more of the same, sand yer burrs, slick up anything moving or lock up prone, no oils it eventually makes dirt. It did the trick without spending any more money on this thing it's been running fine since, so guys if you're having some crazy wild unexplained things happen with the car it might be something crazy wild now explained. Good luck.
one more thing, it did take a good deal o' time patience n persistence fine combing the wires, but cracking open the boxes wasnt to bad, but before u jam a thing into a thing research first..