How to Access brake light relay in 2004 XC90 Topic is solved

Lubectrava · Post by **Lubectrava** » 04 Apr 2018, 16:19

Excellent car so far with few issues at 111k miles. Received the “check stop lamp” message. Side brake lights worked intermittently, top light always works. Changed both bulbs, continued working intermittently and now stopped working. How do I access the rear compartment relays? I poked around today and can find no way to access unless the entire left side panel is removed. Is there a simple way of doing this for a DYIer? Appreciate any responses!

Post by **SuperHerman** » 04 Apr 2018, 16:30

I don't have a direct answer, but I would suggest you look at your connections, specifically the sockets, for corrosion before you start ripping things apart. Take a VOM and check for shorts and continuity.

Lubectrava · Post by **Lubectrava** » 04 Apr 2018, 18:24

Thanks for the response. I completed all those checks and tests before replacing the bulbs. All symptoms point to a bad relay. Just can’t get to the darn thing...

Post by **SuperHerman** » 05 Apr 2018, 09:47

See here:

and here:

Post by **SuperHerman** » 05 Apr 2018, 10:15

I pulled up the instructions in VIDA. What you have to do is basically the same for 5 seater vs 7 seater. Variables are whether you have rear A/C. Basically a few extra wires to disconnect. In VIDA it is found under "85: Other upholstery".

To remove the rear panel you have to remove the various floor pieces that are in the way and then for the panel itself 4 screw caps and the four screws. Then clear the C and D pillar while removing, noting how they have to tuck in relative to one another. You can remove the panels if you want. Winging it - just locate the four screw caps and remove them and the corresponding screws. Then wrestle the panel out. If you have a cargo department, open it up look down and pull the plastic clip (looks like a plastic pin in the middle of the clip) as that is a connection point.

Otherwise you can try the crow bar technique in the linked videos.

So to answer your question, if you want straight access, you have to pull that panel, which does not seem that bad, just don't break any clips.

Lubectrava · Post by **Lubectrava** » 05 Apr 2018, 10:30

Thanks for the interesting videos. The clip for the wiring harness does not require removal of the fuse/relay module and the clip actually replacing the relay is insane! I would prefer not using a crow bar to diatort the plastic panel. Imagine that crow bar slipping and destroying your REM! Yikes! Plus my hands are too large for that technique anyway. There’s got to be a way to either remove the large plastic panel or unclipping and sliding out the relay module. I’ve mucked around with the panel and could not find the 4 caps and screws you are referring to. Don’t currently have access to VIDA :0((

Lubectrava · Post by **Lubectrava** » 05 Apr 2018, 14:39

A solution! Not the best but it easily allows me future access to the relays without removing the entire module or side panel. Was getting quite frustrated and called up the a few Volvo dealerships and local shops. Minimum cost at the local guys was $75 plus part ($14. To $17.). The dealers minimum charge was $90. Plus the part ($22).

Here goes. The triangular shaped cover for the fuse/relay compartment has a thin piece of plastic material to lock it in place. This plastic is located at the bottom with a hole for attaching the cover. I cut the small plastic strip and that was the key. It allowed me to pull the panel that holds the storage compartment back about 6 inches with more than enough room to access all the relays. I removed the brake relay (position 5 from the bottom and I removed and installed the relay from position 6 from the bottom (rear fog light relay) into position 5. Voila! Brake lights now work. No check stop lamp message!

For general information, the original part number is no longer available. I called up a few parts sellers and they had 2 different relay pin configurations. A 4 pin and a 5 pin. They had no clue which one shoud be used. The relay in my 2004 XC90 T6 has 5 pins.

I taped the plastic piece together, pushed the panel and cover back in place and you would never know I violated my car LMAO!

Post by **SuperHerman** » 05 Apr 2018, 14:43

Does this help?

Post by **mrbrian200** » 05 Apr 2018, 15:07

That relay pooped on my sisters '03 at 105k miles. I took the failed relay apart...because...I'm like that. It's a stress/metal fatigue issue every one of them will fail sooner or later. Starting MY05+ this relay was updated to a solid state transistor. So on my 2006 S60 it won't be an issue.

Lubectrava · Post by **Lubectrava** » 05 Apr 2018, 17:59

Thanks Herman! You are Super....no pun intended....