Low beam/ high beam issues

[Josh86]

Need help figuring out what happened with my headlights. I was driving the other night and both headlights went out all of a sudden. Low and high beams don't work now but all parking lights still come on and fog lights too. Not sure what happened. Already replaced battery and checked all fuses. Not sure what else to check

 

[Odrapnew]

High/Low beams use the same bulb/filament, so if you lose low beam, it would be the same for high.
The headlight uses a shutter to block off part of the beam for low beams.

Couple question:
How many miles/years on bulbs?
Have you ever replaced them?
Are you able to check if you have voltage at the bulbs?

Mine went out a couple years ago within a few days of each other. I literally just put a new bulb in one side when the other went out the next time I drove it. I’ve also had taillights fail simultaneously.

There’s a (small) chance both bulbs just went out at the same time.

 

[Josh86]

High/Low beams use the same bulb/filament, so if you lose low beam, it would be the same for high.
The headlight uses a shutter to block off part of the beam for low beams.

Couple question:
How many miles/years on bulbs?
Have you ever replaced them?
Are you able to check if you have voltage at the bulbs?

Mine went out a couple years ago within a few days of each other. I literally just put a new bulb in one side when the other went out the next time I drove it. I’ve also had taillights fail simultaneously.

There’s a (small) chance both bulbs just went out at the same time.

Yes, I've checked the bulbs and I think one may have went out but the other one is good. And I've also never had them both go out if only one bulb was bad. But I haven't checked to see if there is any voltage to them.

 

[Odrapnew]

Sorry, to be clear, when I had both bulbs go out at the same time (taillights), I'm 99% sure it was just coincidence.
One failing should NOT cause the other one to fail.

They may fail at the same time because they experience the same usage. Both headlights are on or off at the same time, so they experience the same usage.

If they were manufactured identically, they would last the exact same amount of time, but small differences in mfg process, materials, tolerances....etc yield slightly different parts.

 

[peterk9]

Need help figuring out what happened with my headlights. I was driving the other night and both headlights went out all of a sudden. Low and high beams don't work now but all parking lights still come on and fog lights too. Not sure what happened. Already replaced battery and checked all fuses. Not sure what else to check

Welcome to the Forum.
Before you go digging into this issue, why not get a replacement bulb for the one you think may be bad and see if it works. If it doesn't, then you have another problem to look into. This wouldn't be a battery issue. If you can check for power at the connectors, that would be a good start.
Good luck.

Peter

 

[J_C]

Use a multimeter to measure for power to the bulb connector. Use a multimeter to measure for resistance on the bulb pins (the bulb itself), blown bulb would read infinite resistance. Swap the good bulb into the socket for the questionable one.

Headlight circuit wiring diagram attached... assuming it didn't change between '11 and '14. It's for '14.

 

[ProjectSHO89]

Was the main headlight switch set to "Autolamps" or directly the the "headlights on" position? 1) Have you tried it in each position?

2) Does the flash-to-pass feature work or not?

For both headlights to go out at EXACTLY the same time indicates that the issue is something that is common to both headlights. The odds of dual bulb failure at the exact same time are astronomical. Has to be something in the logic in the BCM that controls both of the headlights simultaneously and the autolamp circuit would be my first suspect.

Keep in mind that this isn't your daddy's electrical system, it's a freakin' computer network that controls everything. The driver's switches are simply inputs to a computer module that has to interpret the switch position and then activate/operate the proper circuits to fulfill the requested action/operation. It is highly likely you will need an appropriate scan tool or equivalent to do much more than first level checks or to swap stuff and see if you get lucky. Forescan with appropriate adapter is highly recommended.

 

[Josh86]

When they stopped working the lights were in auto position, then tried to put them to the "ON " position and nothing. So far I've checked:

1. Both headlight bulbs -Good
2. All fuses(that I know of) - Good
3. Continuity from bulb - Good
4. Continuity from dimmer - Good

• Not sure what the BCM is
• I don't have a multimeter

 

[ProjectSHO89]

Complete answers help....

"2) Does the flash-to-pass feature work or not?"

How did you conclude all of those items a "good" when you don't have a multimeter? A visual inspection cannot determine if an electrical component is "good", only if it is visually "bad".

 

[Josh86]

Complete answers help....

"2) Does the flash-to-pass feature work or not?"

How did you conclude all of those items a "good" when you don't have a multimeter? A visual inspection cannot determine if an electrical component is "good", only if it is visually "bad".

No it does not

 

[peterk9]

Here is another possible cause;
The Lighting Control Module is a device that controls the different lighting systems on your vehicle including the headlight assembly, tail-light assembly, turning lamps, and fog-lights. ... A malfunctioning lighting control module will cause either all or some of the lights in your car to fail.

what does the lighting control module do - Google Search

Processor Lighting Control AH6Z-13C788-A | Auto Nation Ford White Bear Lake

AH6Z-13C788-A - Processor Lighting Control

parts.autonationfordwhitebearlake.com

Too bad you are unable to check to see if there is power to the connectors. It would seem that you don't but are unable to verify.
I also agree that it is very unlikely that both headlamps would fail simultaneously due to blown bulbs.

Peter

 

[Josh86]

Here is another possible cause;
The Lighting Control Module is a device that controls the different lighting systems on your vehicle including the headlight assembly, tail-light assembly, turning lamps, and fog-lights. ... A malfunctioning lighting control module will cause either all or some of the lights in your car to fail.

what does the lighting control module do - Google Search

Processor Lighting Control AH6Z-13C788-A | Auto Nation Ford White Bear Lake

AH6Z-13C788-A - Processor Lighting Control

parts.autonationfordwhitebearlake.com

Too bad you are unable to check to see if there is power to the connectors. It would seem that you don't but are unable to verify.
I also agree that it is very unlikely that both headlamps would fail simultaneously due to blown bulbs.

Peter

I checked where the bulbs plug in with the Continuity tested and there was power. Is that the same as the connector?

 

[peterk9]

I really haven't looked closely at the headlamp set up in any of my previous Explorers. The connectors are usually at the end of the wiring harness and plug into the bulb. or its base.

Peter

 

[ProjectSHO89]

Again, complete answers help....

"How did you conclude all of those items a "good" when you don't have a multimeter? A visual inspection cannot determine if an electrical component is "good", only if it is visually "bad". "

 

[ProjectSHO89]

Here is another possible cause;
The Lighting Control Module is a device that controls the different lighting systems on your vehicle including the headlight assembly, tail-light assembly, turning lamps, and fog-lights. ... A malfunctioning lighting control module will cause either all or some of the lights in your car to fail.
what does the lighting control module do - Google Search

Processor - Lighting Control AH6Z-13C788-A | Auto Nation Ford White Bear Lake ​

AH6Z-13C788-A - Processor - Lighting Control

parts.autonationfordwhitebearlake.com

The FTP feature bypasses the FLM (Front Lighting Module aka the headlight switch module) by sending a network message from the SCCM directly to the BCM to operate the lights.

This is probably going to need a capable scan tool or the aforementioned Forscan in order to make any real progress.

 

[Josh86]

Again, complete answers help....

"How did you conclude all of those items a "good" when you don't have a multimeter? A visual inspection cannot determine if an electrical component is "good", only if it is visually "bad". "

Again, complete answers help....

"How did you conclude all of those items a "good" when you don't have a multimeter? A visual inspection cannot determine if an electrical component is "good", only if it is visually "bad". "

 

[J_C]

^ Something went wrong, cannot see your reply text. I'd get a multimeter, even a low end $10 one is useful for many automotive troubleshooting techniques.

 

[Marauderleader]

So did the OP replace both bulbs or repair the connectors that tend to melt inside these headlights? I’m guessing that we will never know...

 

[gday]

So did the OP replace both bulbs or repair the connectors that tend to melt inside these headlights? I’m guessing that we will never know...

Unfortunate that threads die like this - but maybe with my help we will know. ;-)

I just went to the store and on my way back, both headlamps died. Since I live in the middle of nowhere and its night and raining it was a scary drive for 1 mile with just fogs working. Same symptoms as the OP. Taillights work, fog lights work, flash to pass operates the shutters but both headlamps inop regardless of auto mode or not. As its now raining work on this will have to wait - was just hoping for some clues as I find it nearly impossible to believe both bulbs died at the same moment in time, but I guess that's where I have to start.

 

[peterk9]

Unfortunately, it is not all that unusual for members to not follow up on their posts regarding any resolution to their issue.
Do you have HID? In any case, the L & R headlamps have their own fuses so that should rule out a common fuse issue. I don't know if a bad ground would necessarily cut the power to both headlamps. It would have to be a common ground.
Perhaps now that the thread has been reactivated, someone will be able to offer their opinion or solution.

Peter 73s