It's because LED's take VERY little power to lite-up and there is always a small flow of electricity flowing through. You CAN fix this by installing a resistor(s). The highER quality lights usually come withthe resistor already installed. Mine has been in and dinmly on for years now, you get used to it. It's not worth the hastle of installing a resistor if you ask me.
2012 Focus Sport, STexhaust, COBB Filter, Snorkel delete, Toms Tune
SOLD2006 SAP, Draxas Header, MBRPexhaust, CAI, Tuned, FRPP lowering kit, SVT 5spoke wheels, HaloProjectorHeadlights, Niteshaded Side markers/tails, Mazda rearwiper, mustang antenna