[FrostZ]

You won’t regret it! The headlights come with three total add on harnesses, two are clones of each other, which is a harness to convert the headlights to function on cars that did not come equipped with HID and a third harness that is a Add A Fuse. Across different directions from different distributors the Add A fuse is sometimes required per their instructions sometimes it’s not. In my case when I installed the lights the headlight DRL was always in dim mode no matter what when the add a fuse harness was disconnected. The only thing the add a fuse harness did was cause them to go into bright mode when the car is in park during the day, which per the OEM function they should be off entirely. During the day they should be bright, then with either headlights on or parking lights they dim. Instead they stayed dim within the headlights even during the day. My solution was to create a custom wire harness using parts of the add a fuse harness and parts of the harness included for the halogen equipped cars. Following some testing I found that the add a fuse plug was the only way I could engage bright mode with the main harness to the headlight disconnected, so I did the following. After determining the pinout of the OEM connector I was able to route the wire that was formally controlling the DRL within the headlight to the plug formally used by the add a fuse by cutting the plugs off the add a fuse harness with a foot or two of wire, pinning said wire, and inserting them into the connector on the halogen conversion harness that went to the body harness in the location of the DRL pin. I then rearranged the pins within the halogen to up level style harness to just pass the high and low beam pins and grounds straight through. Lastly I placed the two small connectors inline with the side markers to tap the power coming from them that only comes on with the headlights or parking lights on. I then routed that pin from the side marker tap to the location of the DRL control pin on the headlight side. This would allow bright mode to be engaged as power was always coming from the body harness and into the former add a fuse plug thus enabling bright mode, when the parking lights or headlights turned on power from the side marker tap would come into the DRL pin on the headlight, thus overriding the former add a fuse plug and enabling dim mode. This created the desired full OEM function that I wanted, this was all done on a 19 ZL1 so your mileage may vary but I hope this helps!