Rear wireing loom
 

N/side brake light not working 2001 diesel tourer. Bulb changed substituted light switch module, still not working,bulb holder earth checks out Ok but no live feed showing at holder. Possible wireing break in loom. Before I start pulling apart interior to trace cable run,does any one know where nearside loom runs? along floor, over roof,or near side to off side and then at floor level. Can off side brake light be safetly be linked to near sine one without any harmfull effects if I can't find fault?

You can piggyback off the other side but it would be better to find the fault,to be doubly safe install a inline fuse :}

Have you got live feed at the plug itself when unplugged from the light unit ? You say no feed at the bulb holder. These light units can get a break in the circuit at the joins...

rear wireing loom
 

No live feed on Light green/blue feed onwire comeing through body at rear light. I need to know the path of the loom going forward towards the front of the tourer so I can trace a possable broken wire, ie does it go down the nearside sill path or cross over the car and go down the offside sill? If I know where it goes saves pulling alot of internal panels being disturbed.

Just link the O/S to the N/S, all you are doing is what the factory did, but in a different place, not worth the time or effort to trace the fault. The only bug is that the BUS will not tell you if the N/S brake light bulb has gone. For this you will have to trace the open circuit fault.

Pin 5 LSM . You could check at the Lsm plug connection is good LG/U . I presume you have a helper or pushed the brake pedal down with a wedge to check current. Left hand side of boot is a double earth , sometimes one works and the other does not ( if crimp solder on one wire not good ) Remove +clean). Does the reversing light work that side ? Even if ok the other earth may be duff due to bad solder to crimp. You could check continuity from pin 5 LSM to pin 4 LGU on the plug / light unit. I dont know if the lights are bridged inside the boot or not ,as there is a header join, but someone who has installed trailer lights would probably know ! ... ;)

rear wireing loom
 

Have done a link o/side to n/side to get n/side brake light to work. There is no live feed at n/side on wire before multi plug behind body panel in load area. Would still like to know cable path for n/side rear loom to front of car in order to find where fault lies anyinfo welcome.

Yes Richard, at least that's what RAVE shows for the saloon. I don't have separate information for the tourer.

The main harness appears to run down the nearside at floor level then across behind the fascia to the offside but strangely the connection to the LSM isn't shown.

The LH brake lamp is hard wired from the LSM (C0937 pin 5) so no intermediate connectors are involved.

In your first post you said you had substituted a different LSM for the original. Did you configure it to the other ECUs using T4 or TOAF? If not, I would expect you to have an error showing in the instrument pack mileage display which is obviously unsatisfactory.

Simon

I've just experienced a similar fault; no R.H. direction indicator at the rear cluster and it wasn't the bulb. It was a powdery coating on the male terminal of the connector forming a layer of insulation. The female terminal in the connector looked contaminated with something too. I found similar on the tail lamp connection. I could just get a miniature needle file in there to brighten the terminals and normal service has resumed!
This prompts me to ask Richard: did you place your meter probe directly on the bulb socket in the cluster as your original post suggests?

Simon

rear wireing loom
 

As temp repair is working ok will investigate further when time permits. When checking initaly earth was checked by useing power feed from tail light bulb live and stop lamp bulb holder earth terminal inside holder test ok. Stop lamp feed was checked at 3 places a) at pin in bulb holder, b) at joint in feed where feed is split to go to towing socket and c) at the multi plug inside luggage area behind side panel all showed no supply. LSM substitusion did as expected show error on trip mileage but original one put back on car as fault was still there on substituted LSM. Pin checks will be done when time permits.