[FrostZ]

For anyone out there that has purchased a set of the Morimoto/HERO LED headlights you may have noticed during daytime operation the DRL within the headlight remains dim. Those who have bumper mounted DRL's will notice this more as they function normally unlike the headlight DRL's. After contacting the manufacturer it seems there was a fundamental misunderstand of the proper DRL operation causing the improper functionality. Luckily for us the lights come with almost everything we need to fix the issue to regain OEM functionality. Below is a detailed guide on how to create your own harness that I designed, tested, and personally use on my 2019 ZL1.

Step 1 - Retrieve the harnesses for modification:
Packaged with the headlights are three harnesses, two harnesses are clones for each individual housing intended to convert halogen equipped cars to function with the new headlights, and a fuse tap harness. All three of these will be needed to make our new harnesses.


Step 2 - Purchase pins to complete the harness:
During the process we will be stripping and pinning one wire per side to allow our harnesses to function properly. Below I have an amazon link for the kit I purchased that has plenty of spares and both a male and female plug. These plugs are good for practicing if you have little or no experience in wiring before moving on to the real thing.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Step 3 - Prepping harnesses for pinning:
Our harnesses are going to be created using the two halogen conversion harnesses. The female 8 pin connector and dual 2 pin connectors are already properly pinned for our use case, the male 8 pin connector is the focus of our efforts. Follow the very simple video below to completely de-pin the connector. Once all the pins are removed take a flat head and remove the bottom of the connector and weather seal inside, this make pinning the connector later easier.


Step 4 - Fuse tap harness:
Take the fuse tap harness which has two connectors that go to the headlights and cut the wire about 8-12in behind the connector. Note on one side there is a two to one split, you can cut off one side and simply shrink wrap or use electrical tape to cover it up. You can now strip both of the wires ends and take the male pins you bought from part 2 and crimp a pin on the stripped ends. There are plenty of crimping tools available, if you are careful a pair of pliers can be used instead.

Step 5 - Pinning the connector:
Using the chart below pin the male connector as follows taking care that the small locking lip on each pin goes into the small slit in the bottom cover to properly orient the pins.


The wires should look as follows, I put the backing cover on backwards in this photo so disregard that.


Step 6 - Complete the harness:
With all the wires in place push the bottom cover and weather seal back in place, then lock all the pins in by pushing the white pin guide back down. It should look as follows.



Step 7 - Repeat for the other side

Step 8 - Installation!
With the harness complete you can begin the install. The male connector should be attached to the female connector coming from the body. The female end connected to the male plug coming from the headlight. The set of two pin connectors should be connected to the side marker and the connector that originally plugged into it. Finally the single plug that we added should connect to the corresponding socket coming from the headlight. With the harness installed on the driver not the passenger we can see the fix in effect.


The final product

[bereic]

Hi FrostZ

Good writeup... thank you for that.

I have some question on it:

1. do they dimm now, when you turn on the low beam?

2. why do you need to connect the Sidemarkers? Because the PIN 8 is the 12V from the Body for the Headlamp-DRLs.

3. On step 8 you wrote:
"The female connector should be attached to the male connector coming from the body. The male end connected to the female plug coming from the headlight."
I guess you mixed up female/male? Because the connector from the Body is female and not male.

Thank you

[FrostZ]

Sorry for the late reply but thanks!

They now function exactly as OEM dimming and all.

The reason I use the side markers is semi complicated. The 12V supply from pin 8 is on whenever the car is out of park or any of the lights are on. While the OEM DRL's are PWM controlled the Morimoto/HERO lights have two separate DRL inputs, a bright mode, formerly the add a fuse input input and a dim mode within the harness to the body which can and will override the bright mode input. The bright mode input is now connected to the pin 8 of the body harness supply to turn on all the times the DRL is normally on. We connect the side marker supply to provide an input anytime the parking lights or headlights are on, thus overriding the bright mode input causing the headlights to follow all OEM functionalities by dimming.

You are also absolutely right I will fix that right away!

[bereic]

Hi FrostZ

Thx for your explanation.
My car is a 2018 2SS EURO Spec.

So you are saying the PIN 8 entry on the Morimoto Lights is only for dim mode?
And the fuse tab wire connector for bright mode?

I had to splice the uper DRL wire (PIN 8) and run a wire to the "retrofitted" DRLs in the Bumper as the EURO Spec doesn't have them. The Bumper DRL as the OEM Headlight-DRLs are dimming currently as OEM.
The same i had to do for the SM's where I had to splice the Low Beam wire and run wire to the SM's.

Now.
If I understood you correctly I would need to do the same setup as you (beside the fact that on the SS the DRLs are always on, also if in P (Park). Correct?
As I ran this wire from Pin 8 as well to the lower Bumper DRL's, this wouldn't cause any issues?

Would it also be possible to splice the Low Beam wire from the provided harness and run a separate wire in to the PIN 5 ( if i see it correctly on your picture), where the SM wire is going in currently on the provided harness?

Thank you for your help.
And excuse for my english as it is not my former language. :-)