Instrument Illumination

[MWMan]

We had one incident when my wife was driving the car just after we had bought it. Loss of displays etc. It seemed to have all the classic signs of a failing DIM, but it hasn't happened again since. However, I wanted to be sure that if it failed I would have a spare available - and something to play about with!!

[arpi2390]

I just went out to the car, this is what I found:

1. If the car sits in the light and the twilight sensor is activated by light then the dimmer wheel is just a nice turning wheel on my dash but doesn't do anything. In fewer words, the dimmer wheel is useless in daylight.

2. Sticking on a few stickers that were in the car and holding my thumb over the sensor in the CCM did trigger the dimming of the lights, the whole dash went a bit darker from the start and I could adjust brightness with the little wheel.

3. I took my thumb off and put it back on it went full bright and back again and after taking off the stickers and everything going bright again I couldn't trigger it to go dim again. I held my finger for 2 minutes on it but nothing, will have to see what happens in the dark, something might have triggered a fault.

I read somewhere that the sensor isn't always on it samples intermittently so I might have just found the ideal time to stick my thumb on it the first time.

Do you have DRL on the car enabled a the 0 position? Mine only works at the top position I didn't try if that has anything to do with the dimming of the dash or not.

[MWMan]

Many thanks for your investigation. Surprisingly enough, I don't think I have been out at night in the car since I bought it some months ago! So...... armed with your info, I went to the car when it was dusk last night and tried the lights.........Voila, the thumbwheel works. I could scroll the DIM illumination from bright to almost nothing.

So, I went out just now to try it in daylight. No illumination change while scrolling on the thumbwheel!! Put my thumb over the sensor, and it still didn't do anything when scrolling.

The sensor obviously does work, but probably samples once in a while as you said. The scroll wheel does work, but only at night / in the dark. However, it does seems a dim display for reading in the daytime.

So, there are a two possibilities with my display:

1. It all works as it should and is no different to any other V70 with the LED DIM, and its just me that is the problem.

2. While all appears to work correctly, the daylight brightness is actually lower than it should be.

I'm opting for no.1 and going to an optician to see if I have cataracts forming.

However, the in the next week or so, I'm going to try the spare DIM in there to see what difference that has on the display brightness. I'll report back on my findings. Thanks for everyone's input.

[arpi2390]

Based on the pictures you took I'd say your eyes are ok (not an optician so don't quote me on that).

Try the spare DIM, your current DIM is 10+ years old it might have a few issues. Just leave the car standing with the boot open for 5 minutes, then disconnect the battery, leave it for a bit then pop out the old DIM and in with the newer one. The switching of the DIM shouldn't take more then 10 minutes.

While the car is in "daylight mode" what I noticed is that the illumination is at full brightness or perhaps even higher than you can go in the "night mode" maybe something in your DIM is preventing it going to it's highest value. I'd also suggest while the DIM is out spraying some contact cleaner on the connector.

[MWMan]

OK I'll put this post to bed. I changed over the DIM units this morning and both displays are of equal brightness. It was a fairly sunny morning and so bright in the car, but both were the same. I think its probably the green on black that I find hard to read in daylight. I have been used to the BMW / Audi Red displays, which stand out much more.

Thanks everyone for your input.

[D5meister]

Hi John, does the mrs see it ok?

If you wear driving specs that have polarising lenses this can affect contrast a lot with LCD displays

[MWMan]

Steve

my Mrs normally sees everything better than I do, but even she is not happy with the illumination in daylight. Wasn't wearing any specs / sunglasses while looking, so its not that. Next time we meet up you can see for yourself. Chances are, this is absolutely fine and its just us getting used to the Volvo!!

John

[pierremcalpine]

Hi gents,
I've got the same issue. Just noticed this week that I can barely read what's displayed on any of the digital DIM read-outs. I went through the same useless troubleshooting as you guys: tried repeatedly to use the cabin dimmer button which has been doing nothing (in the daylight). I have yet to have a look in the evening but that's my next step. I don't think its the bulbs as it all seems to have happened at once. Please keep this thread active if you figure you issue out!