Yeah it still locks. The blue light comes on when its engaged, its just the backlight for the text. I don't think it has much to do with ARB and more to do with a light bulb or LED. Maybe they stopped making these and I'll get a set of new switches. I also want to wire in a AutoMeter ProLite into the rear locker switch, mounted on the tranny hump in front of the shiters so I will be able to know without looking if I have any lockers engaged, since the rear has to be on for the front to be on.