C5 Boot Lights Not Working

[Derek58]

I have a 2004 HDI estate and both interior lights in the estate boot do not work. I have changed the bulbs and the C30 5amp fuse. Can anyone help me please?

 

Derek58.

[paul.h]

Welcome to the forum.

 

Have you checked if the lights work with the engine running or just after stopping the engine, since if the car is in economy mode all the interior lights do not work, as well as the radio ? If they still do not work when not in economy mode, had the fuse you changed failed ? Did you get the fuse number from your handbook, since in the one with our 2007 C5 it has the glovebox fuse F7 (5 amp) as being for the interior lamps and there is not a fuse F30 listed (or any C fuses). In the RTA manual for the 2001 to 2004 C5 it also lists fuse F7 for the interior lamps as well as the 12v sockets but is a 20 amp fuse.

[Derek58]

In my handbook it states on page 128, fuses under the dashboard (Fuse box C2) G30 5amp Boot Lighting. I have changed the fuse and the bulbs with the engine running and engine not running no joy.

[paul.h]

Is your car the 2001 to 2004 mark 1 model or the 2004 to 2008 mark 2 facelift one ?

 

Our 2007 C5 estate does not have a fuse in that position but the G36 to 40 ones are used for the towbar connector (36) and the electric/heated seats (37-40) if it had them. These fuses take a direct supply from the battery via a maxi fuse in the engine fuse box. If you have a voltmeter, you can check for 12 volts at these fuses to see if the maxi fuse is working.

 

Maxi fuse MF6 (80 amp) is the one that feeds these G fuses and this is the same in the mark 1 and mark 2 models. The maxi fuses are located below the top layer of fuses in the engine fuse box and are numbered from 1 to 8 from the left when looking from the front of the car. In the RTA book for the mark 1 C5 it labels MF6 as 80 amp, boitier 12 fusibles habitacle - so it covers the 12 G fuses. For the mark 2 C5 it labels MF6 as 80 amp, sieges chauffants et/ou electriques - so it covers the seat heating/electrics. I have not had to replace a maxi fuse so I am not sure how to get to them.

[Derek58]

it is a mark 1. Thanks for your help I will take it on board!

[tampenny]

i have the same issue now any resolution please ??

[paul.h]

If it is not the bulb or a fuse then maybe the bulb holder or its wiring - check for a 12 volt supply when the bulb should be lit and for an earth from the bulb holder.

[tampenny]

no 12v supply to the lamps, continuity on earth fine,

checked wiring diagram in the Haynes manual but no sign of a switch,

has to be a switching mechanism surely.....!!!

any ideas please ???

[paul.h]

Did you check for the 12 volt supply with the engine running or just after stopping it so it was not in economy mode ?

 

Are you having problems with the boot lock since the bsi that puts on the boot lights probably takes a signal from this that the tailgate is open. You could try with the tailgate open but close its lock around a screwdriver to see if this makes a difference and should switch off a supply. If not related to the lock then you may need to check the wiring from the lights back to the bsi - at the light end read the wire number on the wire using a magnifying glass and at the bsi end (glove box fuse box) find the same numbered wire and then check for voltage here and if ok check for continuity along the wire.

 

I had a quick look at your recent posts to see which car you had but could only find a picture of your heater panel indicating it is a mark 1 C5 so I have edited your profile with this info. If you edit this with your car details (year, engine, trim) it saves you having to mention it each time you start a new topic or saves us having to guess.

[tampenny]

Paul,

thank you for doing all the leg work with the complicated forum info stuff....yes MK1 C5,

found the problem in the usual place !!!!..........broken wire in the rubber seal at the top of the door,

the door lock motor must send a signal to the BSI which activates the lights,

thank you very much for guiding me to a satisfactory conclusion.

[paul.h]

Pleased you found the cause since it is not an obvious one. I will add this to the common problems topic.