Infocenter/speedometer/tachometer all is black

From CEM to VEM, from LED to lightbulb and more. If you have an electrical problem, like a broken info-centre, search for answers in this category. This is also the place to be when you expect the problem to be of an electrical nature...

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Greengrass
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Infocenter/speedometer/tachometer all is black

Post by Greengrass » Thu Jan 05, 2012 8:33 pm

But they are in working order. Just the illumination is gone.

As I understand there is 3-4 bulbs. But why has all gone at the same moment?

Its not the fuse (number 1), the interior light (rooflights) works.
480 ES - 92 lavender - bought it 2008, every day car, winter-summer
480 ES - 90 red - bought it 1992
460 GLE - 91 red - over 20 years old and absolutely rustfree!
Lexus RX300 - 00

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chriskay
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Re: Infocenter/speedometer/tachometer all is black

Post by chriskay » Thu Jan 05, 2012 10:48 pm

Got to be a connection problem. Remove the panel and remove/re-fit the two multiplugs after giving them a squirt of contact cleaner.
2 Kings; Chapter 9 Verse 20

suddy
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Re: Infocenter/speedometer/tachometer all is black

Post by suddy » Fri Jan 06, 2012 6:51 pm

Is it just the instrument panel? Or do the other dashboard lights (e.g. the clock and heater control lights) as well.
If it's the other dash lights too, check the headlight switch.
If you pull it off with the ignition at position II, you'll notice all your dash lights go out. And I think your parking lights will go out too. The headlight switch is worth a try.
1995 480 S 2.0 237,000 Miles

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pgmm
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Re: Infocenter/speedometer/tachometer all is black

Post by pgmm » Sat Jan 07, 2012 5:37 pm

The main panel lighting is directly connected to +12V when the ignition is ON and the light switch is in the OFF position. The lights are fed by fuse 19, NOT fuse 1, which indeed drives the electronics but not the illumination. So you may want to check the correct fuse, just to be sure :wink: .

When the car´s lights are switched on, the main panel lights are controlled by the rheostat (dimmer), together with the other dashboard lights, that will only light up with the parking lights on. This switching over between "full 12V" and "dimmable via rheostat" is done by relay 4.35 on the back of the main instrument cluster.

If the instrument cluster lights never (i.e. light switch ON or OFF) work, the problem might be in the relay.

I would take the instrument cluster out of the car and test it. Its connections depend on the connector colours (these are well documented) and the pcb is quite simple. If the instrument lights work on the test bench, the problem is in the connectors or in the car itself.
My test would be: connect 12V and GND and check the instrument lights. Activate the parking lights control line (green light should now come on) and hear the relay switch. Connect rheostat output voltage (12 V or a bit less) to the rheostat input line and check the lights.

Good luck!
To be continued...
Peter
-----------------------------
1986 Volvo 480es red 217
1987 Volvo 480es blue 219 (sold)
1993 Volvo 480 turbo automatic red 235 (project)

Greengrass
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Re: Infocenter/speedometer/tachometer all is black

Post by Greengrass » Sun Jan 08, 2012 7:03 pm

pgmm:
- where, exactly, do I find relay 4.35?
- how much and what do I have to disassemble?

For information; I have now checked fuse 19 and it is OK.
480 ES - 92 lavender - bought it 2008, every day car, winter-summer
480 ES - 90 red - bought it 1992
460 GLE - 91 red - over 20 years old and absolutely rustfree!
Lexus RX300 - 00

Greengrass
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Re: Infocenter/speedometer/tachometer all is black

Post by Greengrass » Sun Jan 08, 2012 9:09 pm

The relay do only have to modes, and in this cases it means that the instruments light is on in both modes. One in 12V directly and one via the reostat.

So can it really be the relay that is the problem? Can it get stuck between the two modes?
480 ES - 92 lavender - bought it 2008, every day car, winter-summer
480 ES - 90 red - bought it 1992
460 GLE - 91 red - over 20 years old and absolutely rustfree!
Lexus RX300 - 00

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pgmm
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Re: Infocenter/speedometer/tachometer all is black

Post by pgmm » Sun Jan 29, 2012 9:35 pm

Relay 4.35 sits on the back of the instrument cluster, under a white plastic cover. (I have read suggestions that in later models the relay sits somewhere else)

The contacts of the relay could be contaminated so it would not connect in any position, but I agree it is not very likely that both positions ("direct 12V" and "via rheostat") do not work.

After you have taken out the instrument cluster, testing the lights is very simple. What modelyear is your car, what colour connectors does your unit have: yellow+blue, yellow+red, green+grey?
To be continued...
Peter
-----------------------------
1986 Volvo 480es red 217
1987 Volvo 480es blue 219 (sold)
1993 Volvo 480 turbo automatic red 235 (project)

Greengrass
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Re: Infocenter/speedometer/tachometer all is black

Post by Greengrass » Tue Jan 31, 2012 9:34 pm

This evening I have done some testing and work to find out what is wrong.

To start with, my car is a 1992 years model. The relay is not on the back (under a plastic cover) on the instrument cluster. But I have an instrument from a donor car (1988) and there is the relay on the back, under a plastic cover.

Well, this evening I dismantled the instrument cluster, and then mounted the one from the donor car (year 1988).

Then this happened: The instrument light works! But as I finally mounted the headlight switch, it went dark again!
But when I turned on the parking light, the instrument light worked, but just the moment between off and parking light, if you see what I mean. This phenomenon did not happened with the original instrument, that whas all just black.

The 1988 instrument can not directly be put in a 1992 car, for exampel when I turn on the left direction indicators, then the red light bulb for "door open" flashes...

Should I look for a new headlight switch?
480 ES - 92 lavender - bought it 2008, every day car, winter-summer
480 ES - 90 red - bought it 1992
460 GLE - 91 red - over 20 years old and absolutely rustfree!
Lexus RX300 - 00

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glasgowjim
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Re: Infocenter/speedometer/tachometer all is black

Post by glasgowjim » Wed Feb 01, 2012 12:15 am

a replacement second hand headlight switch will cost you £4 + postage which wont be much given how little the switch weighs.

I know a man who has spares :rofl:

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glasgowjim
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Re: Infocenter/speedometer/tachometer all is black

Post by glasgowjim » Wed Feb 01, 2012 12:18 am

On the main site home page go to down loads and and you will see the relay layout.

Greengrass
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Re: Infocenter/speedometer/tachometer all is black

Post by Greengrass » Wed Feb 01, 2012 7:16 am

1. I shall test another headlight switch from a friends 480.

2. The realay layout yes, but are there really any relays in the relaybox that can affect this malfunction? Which one?
480 ES - 92 lavender - bought it 2008, every day car, winter-summer
480 ES - 90 red - bought it 1992
460 GLE - 91 red - over 20 years old and absolutely rustfree!
Lexus RX300 - 00

Greengrass
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Posts: 34
Joined: Wed May 05, 2010 10:32 am
Location: Arvika, Sweden

Re: Infocenter/speedometer/tachometer all is black

Post by Greengrass » Wed Feb 01, 2012 7:07 pm

Now I tested another headlight switch. No different.

So its back to the relay. Butwhere do I find it?

In the relaybox or somewhere under the dashboard?

This is a 1992 model, so the relay is not on the back of the instrument cluster.

It cant be inside the instrument cluster box?
480 ES - 92 lavender - bought it 2008, every day car, winter-summer
480 ES - 90 red - bought it 1992
460 GLE - 91 red - over 20 years old and absolutely rustfree!
Lexus RX300 - 00

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glasgowjim
480 Is my middle name
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Re: Infocenter/speedometer/tachometer all is black

Post by glasgowjim » Thu Feb 02, 2012 6:40 pm

There is no relay inside the instrument cluster of a 92 car with grey / green sockets on back.

switching over non identical instrument clusters causes all sorts of ( minor) problems.

Greengrass
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Re: Infocenter/speedometer/tachometer all is black

Post by Greengrass » Fri Feb 03, 2012 8:06 am

Hmm... anyone who know where this relay is (not where it not is)?
480 ES - 92 lavender - bought it 2008, every day car, winter-summer
480 ES - 90 red - bought it 1992
460 GLE - 91 red - over 20 years old and absolutely rustfree!
Lexus RX300 - 00

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pgmm
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Re: Infocenter/speedometer/tachometer all is black

Post by pgmm » Fri Feb 10, 2012 11:03 pm

The May 1991 wiring diagrams (Section 3 (39) of the Workshop Manual) suggests there is NO relay 4.35 anymore. All dashboard lights are always on via the rheostat, whenever ignition is switched on (via the light switch and fuse 10).
Given your observation that the instrument lighting works shortly between light switch positions 0 and I, you may want to try another light switch.

On the green/grey instrument panel you can test the panel lighting (3 normal bulbs and 1 halogen bulb for the info center LCD) by connecting 1.2 (green connector pin 2) to GROUND and 1.5 (green pin5) to +12V.

Good luck!
To be continued...
Peter
-----------------------------
1986 Volvo 480es red 217
1987 Volvo 480es blue 219 (sold)
1993 Volvo 480 turbo automatic red 235 (project)

heavend
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Re: Infocenter/speedometer/tachometer all is black

Post by heavend » Sun Jan 12, 2014 7:47 am

Suggest you download the schematic diagram from this website and buy a cheap digital multimeter. Power for all the instrument panel lamps goes from the battery to the ignition switch/light switch/fuse/rheostat (dimmer) to the lamps. Easier to diagnosed than randomly guess and change parts. You will use the diagram and multimeter again because I promise you the 480 will get another electrical fault.
The electric going to the lamps has to come back to the battery somehow....check that there is a good earth return. Electricity is like the Circle line, goes around in a loop, hence the name 'circuit'. Amazing how many folk miss the return path.
I have a couple of Alfas that are supposed to have rubbish electrics....I have had 7 Volvo 480s and not one of them was put together as well as my Alfas....the plastic is rubbish, electrics unreliable, leak like a collander, poor NVH...but I love 'em.

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glasgowjim
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Re: Infocenter/speedometer/tachometer all is black

Post by glasgowjim » Sun Jan 12, 2014 9:56 am

How many fuses do you have in the fusebox as 92 was a transition year for a lot of parts.

26 or 32 fuses.

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glasgowjim
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Re: Infocenter/speedometer/tachometer all is black

Post by glasgowjim » Sun Jan 12, 2014 12:15 pm

Cant believe that I think i know the solution to this one . 480 volvos have a mind of their own and just sometimes all the circuit diagrams in the world wont help you and you have to go onto a belt and braces approach to the problem.

Check fuse 24 the mirrors fuse on the 26 fuse fusebox. If its blown replace and sit back and watch your instruments kick back into life.

Regardless first step now is to check ALL fuses .

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