Product updated on 2019-05-11, SBX Parts - 4HIGHGM99, Wiring harness to convert HID headlights to 4 high operation on negative trigger headlight system such as 99-02 GM trucks., If cutting and soldering is not your strong point then grab one of these plug and play 4 high wiring harnesses so that when you turn your high beam headlights on your low beams will also stay , A 4 high headlight conversion kit will keep your low beam headlights on when you switch to high beam. This does two things. First, it provides mor elight on the road and close in front of you when on high bemas. Second, it provides instant light in front of you when switching back to low beams. This is very useful on vehicles with HID headklights as they can take a second or two to come to full brightness when first truned on.