TLDR: Trust the manufacturer’s directions (usually) and the ignition must be on when testing turn signals.
As I was typing this, I got a shipment notification from Tom Wood’s Custom Drive Shafts that my order shipped. Fast turnaround for custom work!
After the remote starter mystery box fiasco, I still had some time left before I had to get ready for work so I figured I’d work more on the exterior lighting. I had to replace the headlights since I removed them initially to retrieve a screw I lost in the grill and left them off while I painted the area where the OE fenders were removed.
Before:
The PO had already swapped out the OE headlights for these unmarked LED headlights. They work fine and don’t look horrible, so they’re staying for now.
After:
When I purchased the Metalcloak fenders, I also purchased two pairs of their LED dual function LED marker/blinker lights and their LED flasher relay. I installed the flasher when I was messing around with the steering column earlier.
The kit is rather nice. The LEDs appear to be made by Maxxima and have all the required circuitry to make them work already there - I assume in the molded area with the “Maxxima” marking between the bullet connectors and the LEDs.
The kit came with several lengths of wire, bullet connectors, butt connectors, and ring terminal connectors with instructions to build pig tails. I originally was going to swap out the bullet connectors for heat shrink spade connectors I had on hand, but since the male bullet connectors were already attached to the lights with molded-on connectors I decided to use the provided bullet connectors and just cover them with heat shrink, which will also help in identifying them with different tubing.
Speaking of heat shrink tubing, if you use an electric heat gun to shrink tubing, you really need to get one of these nozzles. I have used this thing on hundreds of connections between two boats and five cars. It saves time. I place the gun so it is resting on it’s intake (it has feet to allow air flow and is designed to be used this way), I then move the shrink tube wrapped wire into the hot air flow and it shrinks immediately all the way around because it is engulfed in hot air instead of the hot air just blowing by. Of course, you can still use it the normal way and bring the gun to the wire.
Here are all the pigtails built.
I was almost out of time but wanted to test one of the lights. I went to connect everything, but it was difficult. Even though the connectors Metalcloak provided were not heat shrink, they still shrunk a little and the bullet connector fit was extremely tight. I used some dielectric grease as lubricant was able to get them together (the fit is so tight the dielectric is not impacting conductivity). I need to work on the connectors some more as they’re still not completely pressed together.
Metalcloak’s wiring instructions were interesting and confused me at first after reading several of the LED marker/turn signal threads on the forum. These lights only use the white/yellow and white/green (driver) white/tan (passenger) wires from what I think was the side-marker light connection (the connection with the small round bulb with two wires instead of the connection with the spade three wire connector, I can’t remember which is which since it has been so long since I removed them). It also has you ground the LED’s white wire to the chassis where the other lights are grounded. They tell you several times throughout the instructions to not cut the other connector and just leave it alone or else! I decided to trust the instructions (there was a typo or two and they forgot to mention the driver and passenger blinker wires were different colors, which through me off, but their wiring diagram was correct). The instructions were also written for someone only installing a single dual function LED on each side, so I had to adjust since I was installing two LEDs per side, which their fenders allow.
Here is the passenger side temporarily wired.
I wanted to test everything before wasting time splicing two wires to one, so I used WAGO lever nuts in the interim. These things are very handy. I’ve frequently used them on connections that I know will stay dry without issue, but I will need to use something better here. They make 2-wire to 1-wire spade and bullet connectors, but I do not have any and will probably just figure out how to do it with what I have but still make it easy to disconnect.
After everything was connected, I decided to test it out.

Parking lights: marker worked

Head lights on: marker worked

Parking lights, turn signal: NO blinker, marker worked

Head lights on , turn signal: NO blinker, marker worked
Got mad and thought the instructions were wrong and I’d have to install extra circuitry after all. Then I remembered that the turn signals only work if the ignition is on.
Turned the ignition on…

Parking lights: marker worked

Head lights on: marker worked

Parking lights, turn signal: blinker worked, marker worked

Head lights on, turn signal: blinker worked, marker worked
I will finish up the install tomorrow and swap out all the rear brake/signal/reverse bulbs for LEDs as well. I decided against new sealed LED fixtures for the rear since changing the bulbs will pretty much accomplish the same thing for much less.