Citroen C5 2010 main beam not working, relay location ?

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Orcapod
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Citroen C5 2010 main beam not working, relay location ?

Post by Orcapod »

Hi all,

first post! I found this forum a big help trouble shooting a few problems on my C5 for far to date. one problem I am a bit stumped on though and led to me posting is the main beam suddenly not working. apologies if this has been covered before but I cannot seem to find the info I need on the forum. my full beam has stopped working. all other lights ,side lights , fogs ,indicators ect are all functional. I checked the main beam fuses left and right F14, F15 both fine. I havent actually checked the bulbs yet but do not believe this is the problem, the likelyhood of 2 bulbs blowing at the same time is obviously slim but will check to rule that problem out . when I twist the stem on the comms 2000 unit to main beam, the green dash light comes on, because of this I do not think its the comms 2000 unit is at fault although this is only an assumption(I am by no means electronically minded, thats why im here posting now)!. I also did a BSI reset after watching a video on youtube but a bit dubious as to whether the reset actually worked. could be faulty BSI? so next thing to is check the relay...............wheres the bloody relay! I have looked at a few fuse diagrams online and in owners manual but cant find anything to point me to the correct relay. I have had a poke around under the bonnet and can see what I think are relays but dont know which one would be for the main beam (boxy looking things with alot of wires hanging out of them). If anyone could tell me the exact location for the main beam relay that would be really helpful. I have never used a multimeter/voltmeter nor do I own one but seen they are under a tenner in halfords so will pick one up if I need to. Someone did say to me swap the relays about to find a faulty one but not sure about that either.

I am determined to get to the bottom of this problem without taking to garage( I am furloughed with f**k all else to do and enjoy the learning).As to date during the lockdowns I have replaced to 2 faulty wiper motors, one window regulator got at least 1 more of them to do. fixed a leaky wind screen, taken out the carpets to dry after being completely soaked due to leak (horrible job) and have at least 2 other problems to get through. Oh I just love my C5

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mickthemaverick
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Re: Citroen C5 2010 main beam not working, relay location ?

Post by mickthemaverick »

Hi and welcome to the forum. If you post up your VIN, which will be obscured so only admin staff can read it, one of the chaps will hopefully be able to point you in the right direction. My C5 is a MK1 so will be different to yours so I can't help myself. Good luck with sorting it out. If you have spare time take a more general look around the forum from the board index above and take in the Off Topic Chat Lounge where there are many interesting and amusing threads to be found. They are a great bunch of chaps on here so join in anywhere that takes your fancy. :)

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Paul-R
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Re: Citroen C5 2010 main beam not working, relay location ?

Post by Paul-R »

A couple of questions.

What sort of lights do have on you C5? Normal halogen or HID? Does your key fob have headlamp flash or boot open as the centre button? If headlamp flash, what does that do?

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GiveMeABreak
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Re: Citroen C5 2010 main beam not working, relay location ?

Post by GiveMeABreak »

Pop your VIN for me and I'll see which system you have, so we can advise as to which components control what - but if this is a DW10CTED4 engine (163 BHP) with halogen lights and Hydraulic suspension, the Main beams are controlled via the Fusebox and that is Fuse F16. Relays are integral to the engine fuse box and generally non-user serviceable.

But it is not unheard of for the other bulb to go shortly after one goes.

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Re: Citroen C5 2010 main beam not working, relay location ?

Post by RichardW »

Check the bulbs before you go any further - what normally happens is that one is gone but you don't realise, then the other goes, and it all goes dark!

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Paul-R
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Re: Citroen C5 2010 main beam not working, relay location ?

Post by Paul-R »

It has to be said that it's usually the dipped beam bulbs that fail far more often than main beam bulbs.

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Re: Citroen C5 2010 main beam not working, relay location ?

Post by wheeler »

RichardW wrote:
09 Feb 2021, 15:22
Check the bulbs before you go any further - what normally happens is that one is gone but you don't realise, then the other goes, and it all goes dark!
What he said 👆🏻
You see everything all dark & think both failed at the same time but in fact one of them failed earlier. You assume the worst thinking its an electrical fault but its just 2 failed bulbs.

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bobins
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Re: Citroen C5 2010 main beam not working, relay location ?

Post by bobins »

Have you had any sort of battery issues recently what with it being winter and cold ? Has it been slow to turn over or had the 'Economy Mode' warning up on the dash ? These C5s are prone to unpredictable madness if the battery is a bit iffy.