Diode Dynamics Fog Lights Installed

[chiko]

A plan:

Notes:
Purpose of Pin #13 on Headlamp assembly is unclear. 2022 Schematic shows BCM 5 to be a white wire but this 2024 hybrid is brown and the purpose of BCM 5 is Module communications network.
2022 Schematic shows a DRL to Pin #1 but 2024 model hybrid has no wire to this pin.

See this link. With caution about when to disconnect the bumper harness and ability to move the wheels and make access to the fasteners better

EDIT 1 Aug 2025. Not sure what to make of this. At near dusk condition, the default Auto headlight works with the low beam bottom lights, but the upper DRLs are off. Same with selecting low-beam from the switch. Perhaps in darker conditions I get a a combination of low beam on the lower side and DRL on the upper side? I want my amber fogs to be available in any state:
1) No front whites (I could be OK with some white upper DRLs in auto-mode)
2) DRL whites
3) Low-beam whites

It would be nice if the the fogs auto-shutoff because there is no power to the DRLs or the low-beams even without a positive signal for HI but at this point it is not a priority for me.

EDIT 25 Aug 2025: Bad plan. Turns out that Pin 8 White (fuse or circuit breaker) is constant hot in that it doesn't even care if the key is inserted, never mind what position the key is in or the state of the headlamps. Not wanting to drain the battery I am going with a more conventional Low Beam/DRL configuration Pin 3 Brown/Blue. It was dusk when I tested so not sure which mode the head lamps were in.
I discovered this problem because I had pinned the back of the headlamp connector at Pin 8 with 20G solid wire rather than vampire tap. It was hot when I checked everything out but the later on during final install it was NOT and the connection was loose. This peaked my curiosity so I did some trouble-shooting. HOT in RUN Check. HOT in ACC Check. HOT in whatever is between OFF and ACC Check. ITS JUST ALWAYS HOT!

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[chiko]

Some proof of concept for the plan.
I was able to wire up the fog back-lights to the turn signal in part. The front facing running lights were very dim, less than 1 volt, and unable to drive the fog back-lights. When hazards were turned on both fog back-lights were activated, front facing running lights were bright with no fast flash, and I do not entirely trust my Fluke as it showed about 7V but on a flashing signal. This was what I expected; that the relay body would only handle the high amps of the bright fog lamps and that the LED fog back-lights would be of no significance for the incandescent turn signal lamps.

I wired the relay to body ground for the fog lamp back-lights but did not wire up relay hot so this may change going forward. I was unable to pierce the back of the turn signal connector with tinned 20G and had to approach from a disconnected turn signal connector for testing. Significant stiff weather proofing is present that is different than how I tinned and pinned some rear lights to the tail-lights.

So far just fog back-lights; no bright fogs.

 

[CNJFF]

You definitely need a separate power source. Everything is computer driven and/or set up to run a certain amount of power. They build things to the minimum needed. That's why all these kits have their own power wires. The amber backlight is 0.15A. The white is 1.2A (yellow 1.6A). Bright overrides backlight (turns it off)



When I was planning out my fog light install, one set up I looked at was enabling the backlights on demand similar to you. I was planning to try another DD relay harness to run each color of each light. The outputs from the BCM would be the power to the relays (overall fog on/off via the switch in the cab). Then the marker light circuit or headlight circuit would control each color of the fogs. Not sure how much it would draw on each, though. Should be minimal.

You could simplify it further by not separating left and right. Combine the backlight and bright wires respectively. Use standard automotive relays - one for backlights and one for brights. I don't know the max amperage from the BCM but could potentially use one output.

 

[Cancunbadlands]

This mod is not for the Tremor trim, right???!!

 

[chiko]

Today I back-stabbed the turn signals and driver's side headlight with 20 AWG solid core bell wire; confirmed expected voltages; "secured" the contact with a zip-tie around the insulators and terminated with a fully insulated female spade. With a digital VOM the turn signals wandered all over the place because of flashing. I recognize this is not the most reliable connection for the fog-lights but those are not critical and I still have memories of vampire taps breaking my first two vehicles as a young person.

The head-light was consistent 14+ V in the RUN position and very low voltage in the ACC position. I note that I don't drive all that much and the Battery Management System may be unpredictable about what is constant hot. My fogs are amber but I am tempted to run them independent of the low beam/daytime state. I also note that the DRLs are OFF in the parking gear vs a drive gear which may be important to off-roaders that I am not.

Next step is to run a ForScan DCT check to establish a baseline. Vaguely do all the electrical connections to establish functionality including full fog light loads. And then re-check the ForScan for faults. My goal is that Fogs work independent of low-beam, fog amber back lights can handle the load of either turn signal; and that turn signals don't fault or act weird if I cut the the link between left amber fog lamp back-light and tie each to separate turn signal wires.

 

[chiko]

95% done.
Lights are "adjusted" but probably too low. At this point the 8" screwdriver shaft is about 2.5 fingers exposed so probably engaged the screw at 2 fingers. It took some doing to find the screw head through the cone.

Weird issue of my own making - I wired the backlights to be supplemental turn signals and cut the blue wire on the Diode harness to keep them separate. Right blinker works FINE utilizing Diode harness, . Left outside lamps on both factory and Diode work fine but the interior indicator and clicker are FAST and annoying. No faults on the generic OBD found with Torque but Forscan DTC finds something. Adding to the strangeness, the FAST flash continues when the Fogs are ON which normally isolates the backlights.

Will try to do some sort of final video soon.

 

[chiko]

Links only show initial preview; you will need to click thumbnail for completion. I am not very good at this.

Dark Morning Version. Shot with FOGS on is upside-down. Shot with hazards and backlights start
upside-down but then flip.

Daylight backlight is NOT very impressive. Amber backlights are visible but just barely. Fogs and backlight work fine lDRLs in Auto position but my operator was only 12 so I went with Auto, Park and hot-wired the switch.

Pre-dawn Video. (Starting to get smarter about making videos.)

I back-stabbed the Driver Side Turn Connector with 18 AWG solid. 20 AWG also worked fine and was easier to work with but the store only had 18.

Looks neatly done but upon reflection, there should be a drip loop for better reliability. Manana.

Reasonably happy with the results. The backlights are normally off and barely show up during day as Aux Turn signals. I like the plus safety, down-play looking like a municipal vehicle with constant amber. I attempted to back-stab the Diode harness with solid wire but the results were not good, loose connection. I ended up with a spade connector but Butt connector would have worked well too. It was what I had on hand.

EDIT: I forgot to mention this. Before I cut the link between Diode Dynamics left and right back-lights., I tested both Ford harness could drive both back-lights from either turn signal without hyper=flash. Both worked fine. After cutting the DD harness left/right, I got hyper-flash but only in the cab indicator and clicker. Outside was normal and only hyper-flash for Driver/Left turn signal.
In Forscan I found in BodyCM Front bulb Turn Outage and changed this from Enable -> Disable. This sounds promising but did not fix the problem of hyper-flash so I went back into Forscan and set it back to Enable. Hyper-flash is rather annoying so I got good and drunk and both the Maverick and I went to bed. Next day -- No hyper flash.

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