Headlight Switch changing from Auto Mode to On

[HammaMan]

Based on the wiring diagram, the headlight talks to the BCM via LIN bus. The issue can reside in either of the 2 modules. Ford made a replacement switch but it didn't work and are supposedly working on another switch. The headlight switch talks to the BCM and the BCM actually controls the headlights directly. The manner in which the 3 different headlights work is all unique in their powering, the headlight switch and BCM should all be the same / similar sans the headlight switches with additional options. So far we've seen it in XLTs to KRs.

I'm quite surprised ford didn't figure this out much earlier given they could have just stuck a listener on the LIN bus here and analyzed where the signal came from. The BCM and headlight switch can both control each other -- one of them is commanding the lights on. If it's the BCM, the light switch will still register the appropriate condition. The HS can say 'turn the lights to x', or the BCM can tell the headlight switch 'the lights are in condition x'. Both would yield the same thing.

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[Davexxxx]

What is the drive mechanism for the truck to turn it's own knob and why does it exist?

It'd take a relay to a motor, wouldn't it?

 

[HSV_MIkeJ]

Latest Update for me since my original post, it has never happened again, don't know if any update might have fixed the problem but haven't seen the issue since my original post.

 

[HammaMan]

What is the drive mechanism for the truck to turn it's own knob and why does it exist?

It'd take a relay to a motor, wouldn't it?

That's not how it works. The dial itself essentially reads a step forward or step backward command. The position of the knob has no bearing on its condition. Rotating right is like hitting a forward arrow to step to the next position.

 

[Platipus]

Bumping this, anyone still dealing with issues like this?
Is there a new headlight switch that’s worth replacing my old one?

This has been taking ahold of my truck for about 4 months. Numerous mornings with a completely dead battery, and random lights flashing in the truck throughout the night. (Caught on camera)

battery is 2 months old, ( ford replacement)
22 f150 platinum, no issues for the first couple years but they haven’t stopped recently.
is the H8 battery the fix?

 

[Platipus]

Hi there. Can you send us a DM with your VIN and dealership info? I can look into this for you.

Is there a fix for this yet?

 

[HammaMan]

This was patched out

 

[Buyer2021]

This was patched out

Please explain what that means?

I experienced this problem for the first time ever yesterday, took me a while to figure out what the chimes were trying to tell me but finally figured out it was the headlights. Mine had been on Auto since day one.

Perhaps unrelated coincidence but I received OTA update DDM-25.12.0 two days ago.

 

[HammaMan]

There was an issue in 22 or so where the headlights would randomly turn on and ford was 'making a new switch' but it turned out the issue wasn't in the switch, it was likely in the BCM and a patch fixed the random headlights turning on issue. This was random post key-off. If there's a 'new' issue where during operation the headlights turn from auto to on, that's new entirely.

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