technical Trunk light not working

Rocky_cpt

Member
Hi all, I am not sure if this question has been posted before on the forum but I recently replaced my trunk light. For some reason the bulb is not working.

Does anyone know what the issue could be? My thinking is the fuse possibly but previously the light was working so I am not sure if it would be the fuse. Any help would be appreciated.
 

Nastaliq

Well-known member
if you replaced the trunk light as a direct for direct replacement (OEM bulb) and its not working, thats likely a fuse.
If it was working and its now not working and its not an OEM bulb, likely the bulb itself but could also be the fuse.
BMWs really dont like non-oem bulbs as the cars voltage system is very very finnicky.

(Ask me about this, i once replaced all the OEM bulbs with white light LEDs purchased as a kit), looked great and bright at first, but car was like a disco after a week, when the lights would pulse on and off- terrible, embarrasingly - I had to go back to stock yellow OEM bulbs).

If you checked the bulb and the fuse and both look okay, check the minimum voltage required on the bulb, sometimes you might get that voltage on startup/welcome but not thereafter, meaning you need a bulb with different operating voltage.

If you checked both and both are within spec, check then pin connectors for proper contact, some contact cleaner can help, or scrape inside carefully with a small flathead - sometimes a tiny bit of corrosion can occur inside and then poor contact, means intermittent light.
 

Riaad

Events Organiser
is the replacement bulb the same spec as the original ?
typically bmw is a bit sensitive to aftermarket bulbs, some work well and others don't.

Id check the bulb, and fuse (however the fuse should be linked to other electronics - so unlikely if you are not seeing any other issues)
 

Rocky_cpt

Member
I bought a replacement bulb from Midas so aftermarket for sure. The spec is the same as the old OEM bulb. I will give Nastaliq's advice a go and see what happens. When I put the bulb in the CID keeps throwing up CC ID 123 😢

If nothing works, I'll wait until I need a service again and ask them to help me out.
 

msm

Well-known member
Also try fitting them the opposite way as some LEDs are polarity specific.
 
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Nastaliq

Well-known member
Sounds like a contact issue, check the pins and the contact points on the bulb itself.
If i remember correctly on my own adventure with lighting, the bendy parts of the light pins themselves sometimes are not bent properly (QC) and they can intermittently contact, giving a rear-tail-lamp failure error.
 
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