Faulty tail light has a red bright light even when the fog light is off.

[Timi]

My right tail light has a bright red light on it when the headlamp is on and the fog light is off. When I turn on the fog light it gets brighter which means the fog light has been turned on.

Also, I noticed for some reason, when the car is turned on at night and the boot is open the bright red light doesn't come on. When you try closing the boot and it gets really close to shutting then the red light comes on.

Please can someone help me

 

[SpikyMikey]

If it's a dual filament bulb it's possible to put the bulb in upside down (ask me how I know) so the brake light filament lights up instead of the tail light element.

 

[whitenemesis]

Has the bulb been replaced at some time? I had curious electrical issues, with different lights coming on when someone fitted an incorrect bulb. Something to do with double filament and wattage..

 

[Timi]

My right tail light has a bright red light on it when the headlamp is on and the fog light is off. When I turn on the fog light it gets brighter which means the fog light has been turned on.

Also, I noticed for some reason, when the car is turned on at night and the boot is open the bright red light doesn't come on. When you try closing the boot and it gets really close to shutting then the red light comes on.

Please can someone help me

If it's a dual filament bulb it's possible to put the bulb in upside down (ask me how I know) so the brake light filament lights up instead of the tail light element.

It is a Mercedes E220d coupe 2015 model, it comes with LED lights and does not have single bulbs.

 

[Timi]

Has the bulb been replaced at some time? I had curious electrical issues, with different lights coming on when someone fitted an incorrect bulb. Something to do with double filament and wattage..

It is LED

 

[Timi]

It is LED and it does not come with individual bulbs. The tail light has not been replaced before.

 

[whitenemesis]

Also, I noticed for some reason, when the car is turned on at night and the boot is open the bright red light doesn't come on. When you try closing the boot and it gets really close to shutting then the red light comes on.

Possibly a broken/exposed wire where they come through the hinge?

 

[whitenemesis]

It is LED and it does not come with individual bulbs. The tail light has not been replaced before.

Just means it gets more expensive! Get the codes read or have a good auto electrician have a look?

 

[SpikyMikey]

If it's a full LED cluster then as whitenemesis says you'll need to get it scanned for faults; it may be a simple ground fault or broken wire, but be aware that if there is an internal issue with the surface mount LED PCB then the lamp unit is probably a throwaway and that can get expensive unfortunately. So much for technology

 

[Timi]

Possibly a broken/exposed wire where they come through the hinge?

You are absolutely right, not sure why the wires were put there. Atleast two wires were separated and atleast 4 more were damaged. I have spent the past hour fixing it. It works perfectly well now. Thank you so much

 

[Timi]

Thank you, it has now been fixed. The wires were installed by the right hinge of the boot. The hinge damaged the wires.

 

[SpikyMikey]

Thank you, it has now been fixed. The wires were installed by the right hinge of the boot. The hinge damaged the wires.

Result

 

[tonysmb]

Good result and thanks for updating the thread as it might help others in due course. Unfortunately, not everybody bothers to update after they've asked for guidance/ideas.