V70 bootlid on an 850...How can i get the brake light working?

[volvo850R]

Evening all, i have put a V70 bootlid on my 850 today which went rather well except for one thing...How can i get the 3rd brake light on the V70 bootlid working? its a different plug to the 850 loom, i tried wiring the original wiring upto it but had no luck. Ive put the 850 brake light in for now but prefer the high level one.

Any ideas?

[p fandango]

may be a silly idea, but if the V70 light is LED did you try the wiring the other way around as they are polarity sensitive

[merc85]

Done this on a friend of mines, didnt have to re wire anything? just plug n play, although the pins looked different

[Dangerous Dave]

I fitted a V70 high level light to my 850 tailgate and just wired it to the original wiring. Like Pedro says check the polarity.

Another problem you might have is the bulb failure warning. The LED light uses a lot less current and the bulb failure light will show on the dash every time you press the brake (does on mine anyway) to counter this you'd need to get the V70 rear bulb failure relay from a donor car (its located in the left boot storage compartment (or whatever its called). There's probably a hack for the 850 relay but I haven't bothered to take it apart.

[volvo850R]

Thanks for the input guys.

The plug on the V70 light is a 10 hole DIN type plug but only has 2 wires going to it.

Looks like i might have a duff V70 brake light as i tried wiring it up both ways with no luck. I will get another from the breakers next week. I probably wouldnt bother but if i dont i will be left with the black etching that goes around the V70 brake light and an 850 low level brake light and i would never be happy with doing a half arsed job!

Has anyone ever tried removing the black etching from the rear window? I have kept the 850 glass as back-up.

[Tomcat]

If I remember rightly there is a relay or similar in one of the boot floor recesses, swap this out for the V70 one and it'll work and you won't get the bulb failure light either, that's what I did on my 850.