S/V/C 2007 S40 Brake light issue

I?ve got a 2007 s40 that is due for inspection this month. I cannot get my passenger side brake light to work. New bulbs, all good fuses, contacts all cleaned and checked. This all started when I took the carpet and seats out and used air to blow all the crap out. I didn?t disconnect any wires, just used compressed air and vacuumed the floors etc.. All I can figure is I blew something loose or blew junk into something. Are there grounds for the taillights under the carpet up front somewhere? I?d like to avoid taking everything back out and tracing wires?

Do those cars have a bulb out sensor relay like the older models? The brake light feed can fail in those and you'll get no brake lights. Start with your test light at the socket for the bulbs and make sure it's getting power when someone hits the pedal for you. If not there then I'd check the fuses and figure out if the car is using the bulb out sensor.

Have you checked for power and ground at the socket itself? Then work backwards from there.

If I remember, I'll try and grab the diagram for the brake lights for you tomorrow if you PM me.

Jordan

I checked for power at the brake bulb sockets and there is no power coming to the passenger side. The wiring, plugs and grounds appear fine in the trunk area.

https://volvoforums.com/forum/volvo-v50-20/2007-v50-check-stop-lamp-104335/

I found this diagram. The top is cut off, but the thread is about light not working.

The circuit is pretty simple. Straight out of the CEM to the lights. I'd probe the back of the connector that plugs into the light assembly (harness side). Do you get power there? No, I'd then go to the CEM and check there. If No, you have a CEM problem.

Note- that I have had the CEM shut off power to a circuit to protect itself if it detects a short.

If you have power at the CEM, but not at the back, check circuit continuity. If you have none- then you have a broken wire somewhere. Over lay a new wire, or start pulling apart the interior to see where you pinched the wire.

*note- the entire tail lamp grounds at one point. So if your other lights are working, it is not a ground side issue*

Jordan

Thank you!