C5 interior lights

[Davidcrofts]

My C5 estate 2004 interior lights on work with the engine running and don't operate when you first get into the car, when you really need them

[vborovic]

Low car battery (economy mode) perhaps?

[GiveMeABreak]

I tend to agree with Vab, how old is the battery and when was it last taken off for a charge? C5s are prone to electrical faults if there isn't a good electrical supply at the correct voltage.

Another pointer is if your enonomy mode is kicking in almost straight away. How long can you operate the radio for before it goes into economy mode?

I would take the battery off and give it a charge, but make sure you follow the BSI reset procedure here. It is important to follow the times as a minimum and don't open any doors during the procedure.

• Put the driver's window down, lift the bonnet and ensure all equipment is switched off.
• Ensure all doors are closed and remove key from the ignition.
• Wait for 3 minutes, disconnect the vehicle battery and wait at least a minute.
• Reconnect the vehicle battery, wait a further minute (do not open doors).
• Switch on the side lights through the driver's window.
• Switch on the ignition and check system's functionality.
• Hold lock button on key down for 10 seconds.
• Remove key open & close door test central locking system.
• Start the engine and complete the system's check.
• Failure to follow this procedure could result in incorrect operation of many BSI related items.

Try this as a cost effective check first and then you can look at getting a Lexia on it to see if there are other problems with the charging circuit / alternator for example. I won't suggest fuses as you say the lights work when engine is running.

[Clogzz]

With the key out, try switching the lights on at the ceiling switch with the driver’s door open.

[GiveMeABreak]

With the key out, try switching the lights on at the ceiling switch with the driver’s door open.

I think Clogzz is referring to the interior lighting switch position - on the X7 there are 3 settings - I can't remember if these are exactly the same on earlier C5s though - they are:

• The interior lamp comes on when you open a door or the boot.
• The interior lamp is deactivated and remains permanently off.
• Lighting is permanent.

[Davidcrofts]

Thanks for your suggestions - in answer to the radio question it doesn't work at all when the engine is not running even with the key switched to the first position

[Stickyfinger]

Has it always been like this or just recently ?

[Hell Razor5543]

Sounds like economy mode is kicking in straight away.

[Davidcrofts]

It has been like this since I've had the car for the past year

[Stickyfinger]

"Parking Shunt" in the fuse box ?

[vborovic]

If you have a key remote with the headlights button, will they turn on/off after you leave the vehicle for a while by the remote? if not, then it's definitely the car's battery ... the economy mode should be clearly visible by displaying a message on the central screen, you didn't comment on this.

[Davidcrofts]

What's the parking shunt? There is a message that says economy mode and the boot lights come on when the boot is opened but only for a matter of seconds

[vborovic]

Low car battery ... 99,9% certain ... if I'm wrong, I'll sell my car ...

[Stickyfinger]

There is a position in the fuse box for long term parking/shipping/dealer etc.....

I would go with the low battery however as VB says.......do the first stage (shutdown) of the BSI reset, charge the battery OVERNIGHT (min 8 hours) or get a new one and then follow the procedure to re-attach the battery (stage 2 BSI reset)

[vborovic]

If the Park Shunt would be active, the supposed economy mode (or what David is describing) would be the tip of the iceberg