Hi guys, I am new to this forum and could use a little help. I bought a 2015 Mustang V6 recently and discovered that the driver headlight stays on high beam at all times even though the switch is set for low beam. When I got to high beam the headlight remains in high beam. I took a peek at the backside of the headlight and noticed the back cover to the bulb missing so someone has been in there. Car only has 10,000 miles. I can't tell if it is the correct bulb D3S but it does say OSRAM on it. Your thoughts are appreciated!

 

The high beam on the headlight works off a shutter that opens on high beam and closes on low beam. Sounds like it is stuck open. Try going back and forth between high and low and see if it unsticks.

 

Thank you.. I will work with it

 

Two quick tests you can do:

A) Remove the bulb and look inside the hole to see if the shield is up or down. Do this before turning anything on so its all cold (Or wait for it to cool down before trying). Don't touch the bulb glass. If the shield looks looks like it is in the correct up position, then it is probably an electrical problem. If it is stuck down, you can try tapping or pulling gently with a pick to see if it frees itself. Don't force it. It should move freely.

B) Stand next to the light bent/crouched over so you can hear the solenoid and have someone turn on the lights ( don't look directly at the lights of course ). If you hear the solenoid flip immediately even though the lights are set to low beam, then it is an electrical problem.

 

Thank you.. yes I am starting to learn about how this system works...Bad design!

 

No, it is actually quite a good design. Has worked well for decades.

 

Did you ever figure issue out and wat the solution was I got a 14 that’s doing same thing on driver side passenger side works perfectly but the shutter on driver side is stuck on lows

 

The posts he made here in this thread are the only posts he ever made on the site. He hasn't been online here since February 2020.

 

well dang yeah idk what I need to check on mine trying to avoid buying a new headlamp

 

Here is The Shop Manual Section on Exterior Lighting!

First thing I Would Check is For Moisture Evidence in the SJB.


KC

 

thanks I’ll look into it by chance wats the SJB?

 

Although This Is For The 05-09 The Basic Premise is the Same!

https://themustangsource.com/forums/...26-7-a-550617/

KC

And Here!

https://themustangsource.com/forums/...on-sjb-550481/

 

Thanks. Btw I did see a video on YouTube where guy replaced his projector instead of buying a new headlight assembly if that’s the issue with mine would it b worth replacing it bc cost is 65 bucks for 2 d3s projectors vrs 400 for a new headlamp