460 turbo dash lights

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Anadinolin
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460 turbo dash lights

Post by Anadinolin » Wed Sep 04, 2019 2:11 pm

Hi all,

I know this topic has be done over a million times, but I need help with my CEM. The large tree lights don't work and the halogen B10D one does not work either. All the little warning bulbs work as expected though. The bulbs are all good. The VDO board has track damage that I have repaired but the fault is the same. This seems like a supply issue...

Can someone give me some pointers on where to look and what to look at?
What good music needs is full deep bass to give it warmth

jifflemon
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Re: 460 turbo dash lights

Post by jifflemon » Wed Sep 04, 2019 5:49 pm

its not just the rheostat been accidentally turned down?

(happens to the best of us!)

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brinkie
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Re: 460 turbo dash lights

Post by brinkie » Wed Sep 04, 2019 7:41 pm

First of all, the instrument cluster's operation is not dependent on the CEM.
Secondly, the 460 doesn't have a CEM at all. ;)

Now back to your problem.

Check if the other dash lights (behind knobs, turbo gauge, in the ashtray, etc) are working.
- If not, check the fuse. If the fuse is OK and you have turned up the rheostat, pull the rheostat and measure the pins of the rheostat plug. Brown wire is ground, one wire is input and should carry battery voltage and the other is feeding the instrument cluster and other lighting. If you bridge those two contacts and there is still no light (and no sparks either, in case you accidentally shortened battery voltage to ground :lol:), then there is a problem further down the wiring.
- If they do work, the instrument cluster itself may be at fault. If you really have a messed up main board, I have a replacement. :)
Robert.

Present cars: 1994 Volvo 480 GT 2.0i Vase Green, 2010 Volvo V70 2.0F Momentum Mystic Silver
Past: 1981 Talbot-Matra Murena 2.2 Rouge Mephisto, 1995 Volvo 480 GT 2.0i Paris Blue

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Anadinolin
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Re: 460 turbo dash lights

Post by Anadinolin » Thu Sep 05, 2019 9:57 pm

I think I am confusing CEM with digital display.
The rheostat is ok, tried a known working one and tried the suspect one in another car, suspect one is a bit dimmer on the second car, so that might also want investigation

Fuses are ok, checked all of the ones under the dash. Found a funky looking aftermarket one so changed it for one that matches the look at least.

Are the bulbs in the centre console connected in series as well? I replaced the bulb in the clock and the digital display came to life briefly/dimly but found another bad section of track on the VDO board.

It smouldered on that section and I cut the power. I have track repair tape which seems to be doing the trick on the section I repaired previously I will try and repair that bit of track and see how I get on...might take you up on your dash offer if I don't get any further with it! One bit after another. I mentioned it's nearly ready for MOT and it must have heard me! :roll:
What good music needs is full deep bass to give it warmth

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brinkie
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Re: 460 turbo dash lights

Post by brinkie » Fri Sep 06, 2019 1:14 pm

No Christmas tree-like connections here, all lights are connected in parallel.
But I can send a fully tested replacement board by regular post, that is not very expensive. I will also throw in some used but working bulbs, got lots of them.
Robert.

Present cars: 1994 Volvo 480 GT 2.0i Vase Green, 2010 Volvo V70 2.0F Momentum Mystic Silver
Past: 1981 Talbot-Matra Murena 2.2 Rouge Mephisto, 1995 Volvo 480 GT 2.0i Paris Blue

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Anadinolin
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Re: 460 turbo dash lights

Post by Anadinolin » Sat Nov 09, 2019 1:10 pm

Sorry for long time between replies, I have been offshore

I managed to get the board reworked borrowing kit from work.
I have now got all the bulbs working and in fact used LEDs from super bright LEDs. The special bulb for the digital section was only 30p but postage and pack was £30 from USA so to make it worthwhile I bought the complete set. I haven't got a solution to the alternator/battery light though as it is bi-directional. 👍

https://www.facebook.com/groups/2204727 ... 208247571/
What good music needs is full deep bass to give it warmth

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Jaster
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Re: 460 turbo dash lights

Post by Jaster » Sat Nov 09, 2019 4:58 pm

That looks fantastic! I've had SuperBrightLEDs in my bookmarks for a while as one of the few websites advertising B10d bulbs, but I've never ordered anything from them, partly due to shipping hassle and mainly because I suspected that the front-facing LED chip would be too directional to allow the light guide to provide even illumination across the info centre display, but it looks like I was wrong about that!

I do have a couple of questions:
- I see they no longer sell a white version, so I assume you went for green. How does that affect the red segments of the display?
- How well does the rheostat work now? I've heard different things from different places, seems to differ on an led-by-led basis.
Current: '94 GT & '88 ES
Former: '89 ES

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Anadinolin
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Re: 460 turbo dash lights

Post by Anadinolin » Sat Nov 09, 2019 6:23 pm

The red shows through still, though I have only been able to see this on the low fuel segment, (new to me car and not driven it yet) slightly washed out but visible enough. and yes I went for green.
I did have to slightly bend the spring pins to allow the unit to twist into the board, the pcb is a little thick.

I'd also advise doing this with the dials out of the car and the pcb removed from the clocks, you can see the condition of the track that the bulbs live on, I have found that the track is easily scratched off by the fittings.

Watch the size of the w5w or w3w led replacements as they can obstruct the glass a bit, also a different mountings of the LEDs will "bleed" light into other places (my abs light is prime example)
What good music needs is full deep bass to give it warmth

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