2000 V70 XC - partial failure of dashboard night illumination - cause and fix?

dromani · Post by **dromani** » 14 Sep 2016, 10:48

The night illumination for my car's climate controls and shifter-position indicator have stopped working. Night illumination for the main speedo/tach area of the dashboard still works OK.

Does anyone have any idea what might be the cause and how to fix it?

Here is some background information.

The climate controls / shifter-position night lighting very occasionally comes back on and works again! The lighting will stay on for that driving session, then when I turn off my car and turn it back on, the lighting in question reverts to "broken". But 99% of the time, the climate controls / shifter-position night lighting fails to light up when I turn on the headlights.

The problem started recently, 3 or 4 days after I got my car back from a garage where it was in to fix my remote door unlock fobs, which had stopped working (would no longer lock/unlock the doors remotely). I suspect that the technician was in under the dash to check electrical connection to various components, and may have left some electrical connector not in fully locked connected position. I would like to check for loose electrical connections, but I don't know where to start looking, so I'm hoping someone can point me in the right direction. As I said, the problem is only with the climate controls / shifter-position night lighting - the speedo/tach area is all OK. Are there separate wiring harnesses for these 2 zones? If so, where is the connector for the harness that feeds the climate controls / shifter-illumination night lighting located, and how do I recognize it?

Alternatively, could this problem be caused by my main headlight switch starting to go bad?

Any and all help greatly appreciated!

Post by **cn90** » 14 Sep 2016, 12:58

The Climate control, search forum archive for Radioshack bulb, 99 cents/each.
Don't lose the tiny blue mini condom, you need it to transfer to new bulb.

The shifter, I use Radio Shack bulb, cheaper than factory Volvo bulb:

https://www.matthewsvolvosite.com/forums ... hp?t=17553

https://www.matthewsvolvosite.com/forums ... =1&t=14201

dromani · Post by **dromani** » 14 Sep 2016, 13:10

Thanks but the bulbs are not burned out, maybe I didn't make that clear. In the two lighting areas I mentioned - climate controls and shift-position indicator - all the night lighting stopped working at the same time. As I mentioned, on very rare occasions - maybe once a week - they all come back on at the same time, but that only lasts for that driving session.

Post by **BEJinFbk** » 14 Sep 2016, 14:06

That's pretty unusual. Usually, dash illumination is like
cheap christmas lights - One goes out, They ALL go out.

But it does leave me with a silly and off base question:
Do the lights that stay on respond to the dimmer?
I don't think this has any real bearing here - Just curious...

I'm with you that the tech left something half connected.
If I were in your position, I would take the car back.
They broke it, let'em fix it.

If you do go chasing under the dash - Follow the Pink Wire.
It's the output supply from the dash dimmer and hits all the
variable dash lighting.

One more wild card question - Stock Stereo or Aftermarket ... ?

dromani · Post by **dromani** » 14 Sep 2016, 14:36

Yes the lights that still work do respond to the dimmer.

I am reluctant to take it back to the garage. One garage broke my remote fob door lock/unlock while they were under the dash trying to figure out why my fuel gauge was stuck on empty. After I got the car back from that garage, the dash lights still all worked. That garage refuse to accept responsibility for breaking my remote fob door lock/unlock, so I took the car to a different garage (a non-dealer Volvo specialist shop, an inconvenient distance away) to have them try and fix the remote fob door lock/unlock. The service counter guy at that garage claimed they were not able to fix it, but when I got the car back from them the remote fob door lock/unlock worked again! However, several days later the illumination lights started acting up, as I describe in my original post. So I'm not sure I trust any non-dealer techs to be playing with around with my car's electronics.

Thanks for the tip about the pink wire. That's the kind of information I am looking for.

Afermarket stereo.

Post by **BEJinFbk** » 14 Sep 2016, 20:43

Taking a look at the diagrams, there's a separation between
the instrument cluster lights and the ECC, Shifter and Heated
Seat switch lights. If they were monkeying around the main
distribution blocks above the drivers left foot on the firewall,
they might have dislodged something. But I'd expect some
other circuits to be affected, too.

Find connector E in distribution block 24 and make sure that the
pink lead in position 10 is firmly seated in the connector block.
I know it's a lot of wire in one place, but don't be intimidated.
Just get some good lighting up in there and have a look.

In any case, here are some PDFs that may be helpful:

98 S-V70 Dash Illumination.pdf: (390.65 KiB) Downloaded 131 times

98 S-V70 Distribution Block 24-A and E.pdf: (173.53 KiB) Downloaded 138 times

dromani · Post by **dromani** » 14 Sep 2016, 23:12

Thank you so much! The lights you mention - for ECC, shifter and heated seat switches - are the very ones that have stopped working, so knowing they show on the wiring diagram as being separated from the instrument cluster lights makes me very confident we're on the right track.
Will I find distribution block 24 in the location you mention above the drivers left foot on the firewall?
Sounds like there are several distribution blocks there - Is there any way to identify block 24?

dromani · Post by **dromani** » 18 Sep 2016, 20:46

See attached photo.
There is a yellow master electrical connector block located behind the driver-side under-dash kick panel, just to the right of the red hood release lever.
You need to remove the kick panel to access it (secured by one Torx screw under the steering wheel, then slides out.).
Five smaller electrical connector blocks attach the yellow master block, From left to right they are color coded white, red, yellow, blue and green.
In my case the white connector on the left side was not fully seated. Just clicked it in and all fixed.

Big thanks to BEJinFbk for pointing me in the right direction!

Post by **erikv11** » 18 Sep 2016, 20:51

Awesome, nice fix.

Post by **BEJinFbk** » 19 Sep 2016, 00:40

Glad you found it!
I don't know about you, but winter is coming
and it's starting to get dark around here...