Relay 2009 Offside Rear Lights Come On On Their Own

[charles]

Re my Citroen Relay.  When the vehicle is switched off with the doors locked after a short period of time it has started putting the off side rear stop tail light on.  It either stays on or it flashes.   If I open any door it stops immediately.  There are no fault codes displayed and no dash board warning lights.  I have checked the earth wire and all the wiring seems fine.  I have changed the bulb.  As soon as the vehicle is started and driven off, they work as they should.  The lights are in very good condition (ie not old and tatty)  Any ideas??

[paul.h]

Maybe your van has parking lights that are set by the position of the indicator stalk ?

[charles]

Would this only put the  rear light on  and  should you be able  to put side lights on with ignition  off ?

[paul.h]

On our cars you can put the side lights on without the key in the ignition. Also the hazards lights will work without the key in the ignition.

 

I am only guessing but your problem could be a fault with the switch block under the steering wheel but since these are expensive you would need it confirming first. Sometimes odd electrical problems can be sorted by a bsi reset or a battery disconnection/reconnection. Your handbook may give advice on disconnecting the battery but I have found the following from the C4 Common Problems topic has not given any problems:

11. Odd electrical problems caused by wrong battery disconnection procedure.

If you need to disconnect the battery and not do a BSI reset procedure, I have found the following has not given me any problems on a 2004 and 2007 C5 and a 2003 C3:

- remove the ignition key from the car

- open the bonnet

- wait a few minutes for the BSI to shut down

- disconnect the battery negative terminal

 

When reconnecting

- ignition key out of the car

- reconnect the battery

- wait a few minutes

- insert the key in the ignition and wait a minute

- turn the key to the first position and wait a minute

- turn the key so the dash lights come on and wait a minute

- start the engine

- take the windows down and up to reset the anti pinch

- reset the clock (and radio on the C3).

 

In the handbook for the 2015 C4 it says to wait at least 2 minutes after switching off the ignition before disconnecting the battery and when reconnecting, to wait at least a minute after switching on the ignition before starting the engine.

[charles]

yes you are right the side lights do come on just  tested again thanks for your help i have not had battery off

 but will give it a try thanks  i am in the ch49 area will try and get it tested

[charles]

which is the fuse for the offside side and stop lights ?

[paul.h]

A look in the handbook lists a few fuses covering the lights but none seem to be for the side lights.

PASSENGER'S SIDE FASCIA PANEL FUSES

Fuses A (amps) Allocation

12 7.5 Right-hand dipped headlamp

13 7.5 Left-hand dipped headlamp - Headlamp height adjuster

31 7.5 Relay supply

32 10 Minibus interior lighting - Hazard warning lights

35 7.5 Reversing lights - Water in diesel sensor

37 10 Brake lights switch - Third brake light - Instrument panel

38 10 Interior relays

42 7.5 ABS control unit and sensor - ESP sensor - Brake lights switch

53 7.5 Instrument panel - Rear fog lamps

 

Driver's pillar fuse box

58 10 Direction indicators

 

Engine fuse box

14 7.5 Right-hand main beam headlamp

15 7.5 Left-hand main beam headlamp

30 15 Front fog lamps

[charles]

Yes that is what i found  i took it  to a friend  he did a test on the diagnostics when i had  driven 30 miles to get there the  light did not come on the fault did not show up but when i got home and parked it came back as soon as i had gone in to house thanks for your help

[paul.h]

Maybe it happens when the bsi fuse box has shut down, which takes a minute or so after the engine is switched off, the key removed and the doors shut. If so then the bsi reset is something to consider. There are various versions of a bsi reset on the internet and one is here http://www.citroen-owners-club.co.uk/citroen/topic/15093-bsi-reset/

 

You could also test the batery voltage in case it is low since sometimes this can cause odd electrical problems.

[charles]

The stop light switch has four wires is it poss able that if unplugged the stoplight might still be lighting  one side  the off side ? i have done a temper y repair disconnect off side stop light and connected to center stop light and I am  going to order new  stop light switch.

[paul.h]

Is it just the brake light that comes on ?

 

If you have cruise control then possibly some of the wires on the switch are for that, but I am not sure. For a faulty switch to be able to put on one light you would expect it to also put on the other side if the brake pedal is pressed with the ignition key removed but all our cars need the key in and turned so the dash lights up (or engine runs) before the brake lights work.

 

In the Haynes manual for the C5 the brake lights have their supplies from the bsi fuse box with 2 wires - 1 feeds the left and high level brake lights and a second feeds the right brake light. However, these 2 wires join at the fuse box. If your van is similar then you would expect all the brake lights to behave the same, unless possibly it is a bulb or earthing or bulb holder problem at the right side - but you have checked these already.