Help - I need an XC90 2005 Brake light wiring diagram

[Peachey169]

Hi all - can anyone give me access to a wiring diagram for the brake light switch / where it gets power from on a 2005 XC90 please?

Thanks

[Voley]

There appears to be a choice of complete wiring diagrams for V70s, XC70s and XC90s on this page:

http://www.volvowiringdiagrams.com/?...ing%20Diagrams

They might be for the American market, but my broadband connection is too slow at this time of night to see if they cover what you want (PDFs between 35 to 45 MB). Hope they work for you.

[Chesney46]

Excellent find. Thanks for the link, I've been having brake light troubles and that helps me out loads. The high level brake light works but occasionally the lower 2 don't and it puts a message up on the dash. I see they are both fed from the REM, which rules out the CEM as being faulty.

[Lancee]

Going to be the relay @ REM 15 from memory?

You should be able to find the info' on here by searching, it has been covered several times.

Top light works, two side ones don't, due to two separate relay circuits, the one for the side brake lights fails, replace the relay.

[Peachey169]

Hi Lancee

Not sure if you've seen the issue I'm having - I have no brake lights at all - the fuses are all ok, have replaced them anyway, and there is no power getting to the brake pedal switch - have replaced the switch as a just in case too.

Any thoughts / advice?

thanks

Rich

[A lex]

Thats a classic symptom of CEM failure due to water ingress. Particularly prevalent on 2005 models form memory.

Its the CEM, I bet ya!

[Peachey169]

Alex

Thanks - will wait and see.
I was under the impression that the feed from the brake switch goes to the CEM and not from the CEM to the pedal?

Rich

[Lancee]

Sorry peachey169, old fool that I am I was replying to chesney 46.

I did some time ago have an intermittent fault (the best kind!) concerning the throttle pedal (V70 D5 185).

I used a circuit from Matthews Volvo site and gradually eliminated everything on the related circuit.

Absolute b'stard to track down, the car had been to a main dealer and a Volvo independent who had failed to sort it.

It turned out it was a fluctuating supply voltage at the pedal which I found out by metering.

The fault was down to a dirty fuse blade!
Car has been A1 for the last 6 months (there's tempting fate!).

None of the above is possibly any use to you, it just might make you feel better knowing someone else has kind of been there, possibly a form of therapy!

If I were in your position I would start at the beginning (in the circuit) and work through voltage/continuity with a multimeter.

It may be worth removing the scuttle and checking for blockages and subsequent water leakage into the car.

Good luck!

[Chesney46]

You are correct Peachy. I have just been studying the diagrams and my problem may be the relay in the rear module. Yours, however, may be in the engine compartment. The switch has a permanent feed direct from the battery through fuse 12 in the engine bay fuse box. The switch then sends a feed to the CEM which in turn sends a feed to the rear module. The high level lamp is directly supplied by the rear module, whilst the normal lamps are feed via a relay and a fuse on a different circuit.
I'm hoping my issue is as simple as a relay. Yours may be as simple as a wire loose on the fuse board. Good luck and well done to Voley for the link. Those diagrams are invaluable now!

[Peachey169]

Guys
Have tried so many things... In the end I've opted to run Fused perm supply independently to the brake pedal switch, and all is now as it should be, with no detrimental effects...
Will monitor and hopefully find the original cause once baby no 2 arrives this coming week, no pressure!
Thanks to everyone for help, advice, morale support and fir those wiring diagrams!
Rich