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Headlight frustrations

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Fri Feb 01 2019, 01:33pm
Member No: #39363
Joined: Feb 18 2015
Location: Manchester
Evening All, total frustration, offside headlight failed the other day, replaced the bulb, still failed, then the nearside failed, replaced both bulbs with new Osram ones, still failed. I have checked what fuses I can (manual not very helpful), the service light will not go out either.
The rear lights are fine, as are the side lights, due to my job, I am working shifts & currently having to drive with my side lights & front fog lights.
Also, my lights are set to auto, so I don’t think it is switch abuse on the controller, or is it??????
Can anybody (excuse the pun) shed any light please?
Fri Feb 22 2019, 02:46pm
Member No: #52246
Joined: Oct 01 2018
Location: Tamworth
1. Have you checked the voltage at the battery with the engine running? If it's much over 14.2 volts your alternator regulator is suspect and you're over-running the bulbs.
2. Is there power at the bulb sockets? (That could be tricky with CAN) You'll need a cheap meter or a voltage tester and check for voltage at the pins with the other end touching a good earth connection. After that it may be time to start digging. I don't know where headlamp relays etc are.... yet.
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 fingerplate (27 Feb 2019 : 09:30)
Fri Feb 22 2019, 03:29pm
Member No: #20936
Joined: Jul 21 2011
Location: Ireland Fermanagh & Galway
Wouldn't it be great if cars had trip switches
1 User said Thank You to iscom for this Post :
 fingerplate (27 Feb 2019 : 09:30)
Tue Mar 05 2019, 09:49pm
Member No: #39363
Joined: Feb 18 2015
Location: Manchester
Quick Update:-
New bulbs & old bulbs, all checked with a spare 12v motorcycle battery, all working fine.
Checked bulb plugs with voltmeter & there is an output (from the brown wire, but not the blue one).
Checked main fusebox under the hood & removed glove box to better access internal fusebox...all ok.
I don't know how to get into the additional battery fusebox to check whats inside.
wits end now, looking like it's off to Citroen for them to have a probable expensive play.
Thu Mar 07 2019, 03:53pm
Member No: #37957
Joined: Nov 02 2014
Location: Yorkshire Dales
Please do let us know the outcome!
I am sick of these modern manufacturers keeping technical information to themselves!
You've paid £20000 for your car and they can't even supply a circuit diagram or even a fuse box layout that matches your vehicle! (the fuse box diagrams in my instruction book do not match the vehicle)
Good Luck!
1 User said Thank You to johntech for this Post :
 fingerplate (07 Mar 2019 : 17:10)
Fri Aug 16 2019, 09:40am
Member No: #39363
Joined: Feb 18 2015
Location: Manchester
UPDATE - having had no luck solving the mysterious headlight problem, i had to take it to a garage in the end (NOT a Citroen dealership)because the MOT had expired.
The garage was an approved Citroen repair shop, after explaining my issues & what i had done, i left the car with them.
One (50% cheaper than Citroen) diagnostics test later, they had to remap the BCU (body control unit), the lights worked, but actually blew this time, something still wasn't right, so they attempted to remap the BSI this time & this threw up an engine management fault this time, on running the diagnotics again, it was highlighting a diesel additive error.....weird, my car isn't a blue hdi.
They ended up contacting the local Citroen dealership (who they hire the diagnostics from), only to be told that they need to input a code that ignores the blue engines & then allows you to remap the BSI. The garage didn't have that code & the dealership said they should already have it, due to leasing the machine from them, so they politely refused to give them the code.
After another phonecall to the head office for servicing, they got the code, inputted into the machine, remapped the BSI & now it works perfectly.
Ironically, after talking to a colleague at work, he told me about an issue he had with a Renault, when he did his rear brakes (electrically operated), he didnt have them plugged into Renaults machines to have them wound back & subsequently ended up with numerous dashboard errors. I had serviced my brakes over winter & manually wound back the calipers, roundabout that time, i encountered the headlight issue........coincidence.......mmm

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