2001 V70, I've been replacing brake light bulbs about every 3-4 months. After yet another "check brake light" warning I just replaced driver side brake light bulb and it doesn't work. These were out of my glove box because I go through so many I bought extras. Bought new bulb and it still did not work. I swapped the bulb and holder from the passenger side and now they both do not work, though the middle light on top of window still works.

Any suggestions?

 

When the top brake light strip works and both side brake lights don't work then I would suspect a fuse, relay or shunt problem. The left and right side bulbs are supplied power through a fuse 11D/3 and the relay (RMI5 in the diagram I have) and then through the shunt. Since both lights are not working look for what's common to both and that would be the fuse, relay and shunt. This assumes both bulbs are not burnt out and that there isn't a problem with both bulb holders, which seems unlikely but possible.

Not sure why you have to replace brake light bulbs so often. Are the bulbs truly burning out or is it problem with the holder(s)? Over voltage or too much vibration can cause bulbs to fail too soon.

Brake lights wiring diagram, REM fuses, relays and shunts diagrams

http://www.box.net/shared/qsa5ibzxl0

 

Thank you for the valuable information and links to wiring diagrams. I checked fuses and all were good. I then swapped the left and right bulbs and holders and the right worked again but the left did not. I swapped them again and both do not work. I'm beginning to think that it's the holder. Not being an electrical guy, is it possible that the brake lights are wired in series and a bad driver side holder, when placed in the passenger side, would not only fail to work in the passenger side but also prevent a completion of the circuit to the driver's side brake light?

 

I’ve never looked at the bulb holders but it is certainly possible power is pulled off one side and supplies the bulb holder on the other side. If this is the case, which does seem likely now, then it could be a problem with the bulb holder, especially if the problem goes away and comes back consistently when swapped. One side working means the fuse, relay and shunt are okay. From what I've read previously these bulb holders can have very flaky connections, lights stop working and with a slap to the brake light lens things start working again.

 

Here's a picture of the melted socket on my 2001 Volvo V70. It's hard to see and troubleshoot this problem in the car. My brake light would only work intermittently, and of course I got the infamous "brake light warning" message on the dash. I got a good used tail light assembly from local Volvo salvage yard for $35 (including bulb sockets).

 

When I got my 2005 V70, the guy I bought it from said the wiper blows fuses sometimes, and one of the brakelights don't work (and gives the message on the dash). He offered to fix it or take it off the price of the car (he had it quoted from the mechanic as a new lighting assembly). I figured I could do it cheaper, so I got him to take it off the price, as well as take the price down more.

I figured the two issues were related and it was a wiring issue (not a relay issue). After all, fuses blow for a reason. The first place I looked was at the hinge of the hatch. I pulled off the wiring cover at the hinge and started pulling out the harness. I pretty quickly found this:



Two wires were completed severed, and every wire had some type of damage to it, due to stress on the wiring harness at the hinge of the back hatch. I soldered the severed wires back together and insulated everything off with electrical tapes (being cautious not to make it too bulky, because it has to fit back in). As soon as I was done, I replaced the wiper fuse, and everything was 100% - no more "Check Brake Light" message.

The light that was not working for me was the third brake light, but all the lighting goes through the same harness, so I can easily see other folks having damage to different wires at this same weak point, leading to a lot of "Check Brake Light" messages. Might be worth taking a look if some of you still have this message.

 

I certainly hope the new V 90's have this problem fixed....

 

Hinge of the Hatch... My english is not so good, might you tell me where to find that? I have same issue, with 2005 V70. Relay build into the REM, no fuses blown and warning light for Brakelight check..
I went trough the whole forums to find plausible solution. My V70 being build in 2004-but on the road only 2005 caused trouble finding proper diagrams. The REM has all relays buildt in, only fuses on it. So all threads speaking of the RM15 relay became useless, so I got stuck.. This might be a solution, if I can locate that hinge place.

 

Hatch = Trunk Door or Trunk Lid (but vertical, instead of horizontal like a sedan). Trunk might also be called boot, if you're more familair with UK terminology.
Hinge = The part that connects the door to the rest of the car, but allows it to move open and closed.

Wiring still has to get from the main car to the hatch lid (trunk door) and it runs along the the left hinge. You will have to remove some stuff to get at the wiring that in my case was stripped from years of opening and closing the hatch without adequate protection.

It's been a long time, so that's as specific as I can remember. Sorry, can't find those old pictures. Hopefully this helps or you otherwise figure out your issue.