At my wits end ! Instruments failure.

[Ulrika480]

Ok here we go (1993 2.0):-

1. Instruments were originally ok apart from a dim but otherwise working infocentre. (Receipt for new Volvo speedo fitted by dealer 5 years ago)
2. From time to time speedo and rev counter needles both 'danced' together and then both woud die after a while
3. Intermittent - sometimes no instruments at all, sometimes all ok.

SO I decided to do something about it:-

1. Volvo specialist confirmed that the speedo and revcounter take their signals from 2 different places > so I presumed circuit board or connectors dodgy.
2. Stripped the dash down checked the multiplugs (seemed ok).
3. Swapped the info centres over as a trial from other clusters
3. Got 2 otherinstrument clusters to try:- 1 no good, 1 from a 95 car where still no rev counter & speedo, but the InfoCentre is perfect in my car!
4. Put the original cluster back - nothing working at all apart from the dash illumination.

I need help - not much electrical knowledge but is there anything obvious you have to 'reset' or fuses to recheck ? Anyone know anyone !?

[Ulrika480]

Anyone any similar experiences or bright ideas that might be worth a go ?

[dcwalker]

I had a session of my instruments suddenly all dying, then coming back again...not quite the same as your problems perhaps, but similar?

Anyway, after trying all sorts of things I found that the Relay to wiring circuit C was faulty - replaced it and everything was fine afterwards and has been since (couple of years now). Maybe worth a look? The relay is the same as several of them so you could just try swapping around....

David

[Alan 480]

Ulrika
sorry can't be a lot of help but did you check that the 'pin-out' on the 93 & 95 are the same? ie BOTH two litre?

maybe different pins, The speedos are the same BUT I think but the wiring varies with year

I have a dicky speedo which 'used to be fixed' by leaning up under footwell and pressing the RHS connection in whilst holding teh dash from coming forwards, this doesn't always work but worth a try?

[Ulrika480]

I had a session of my instruments suddenly all dying, then coming back again...not quite the same as your problems perhaps, but similar?

Anyway, after trying all sorts of things I found that the Relay to wiring circuit C was faulty - replaced it and everything was fine afterwards and has been since (couple of years now). Maybe worth a look? The relay is the same as several of them so you could just try swapping around....

David

Thanks for all replies !

David - Is it obvious which 'wiring circuit C' is ? Also - definitely tried 2 different 2.0 Litre instrument clusters.

Keep them coming please - I will try all out next weekend !

[dcwalker]

Ulrika

As you stand by the driver's side wing, looking towards the windscreen at the triangular relay box, the point of the triangle is nearer the engine, the side with 4 relay positions in it is nearest the wing. The top left hand corner should be empty (it's for the auxiliary water pump which the 2.0 litre doesn't have), next one down is for wiring loom C.

If your headilghts are working fine, then try temporarily swapping it with the identical one at the bottom of the 4 on that left hand side (it's the headlight relay, but identical, so it should tell you what you need to know).

Does that help?

The relay box diagram etc is on the site, in the 92-94 supplementary wiring diagrams/electrical system book PDF.

David

[glasgowjim]

http://www.volvo-480-europe.org/volvo480/downloads.php

look down the list there are 2 relay layout downloads either will do but I would look at the first one

[Ulrika480]

Thanks to both.

[Ulrika480]

Ulrika
As you stand by the driver's side wing, looking towards the windscreen at the triangular relay box, the point of the triangle is nearer the engine, the side with 4 relay positions in it is nearest the wing. The top left hand corner should be empty (it's for the auxiliary water pump which the 2.0 litre doesn't have), next one down is for wiring loom C. If your headilghts are working fine, then try temporarily swapping it with the identical one at the bottom of the 4 on that left hand side (it's the headlight relay, but identical, so it should tell you what you need to know). David

David

I did as suggested and I don't know if its normal, but the headlights worked with the relay removed. When I put the swapped relay back in they didn't. Will order another.
The odd thing is that revcounter worked (so I presumed the speedo would) and I checked the multi-plugs behind the cluster and they were ok, before I put the dash back.
Next time I tried, no revcounter or anything again. I've left the relay out of the headlight slot... they still work

May have to leave it at AR Mills and see if they can fix - or does anyone know a good auto-electrician who can find a fault and fix it ?! (I have 2 spare clusters)

[Ulrika480]

Now back to:-

Pulsing (dancing) tacho and revcounter which makes no sense to me as the Volvo specialist said they are two different feeds? (And no Info centre)

Ideas

[dcwalker]

Hi Ulrika

All sounds a bit odd - sorry my suggestion didn't prove to be the answer!

I'll give it further thought but I think the auto-electrician may be your best bet now.....

Keep us posted - good luck!

David

[jamesy12345]

http://www.volvo-480-europe.org/forum/v ... 91#p172291

Just a thought, might help...the speedo and revs are supplied from different sources but surely they go through the same earth? I know it probably isn't much use to say this but must be a crappy earth somewhere