Several electrical systems stopped working

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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fako2806
480 Newbie
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Joined: Wed Nov 30, 2016 10:23 pm

Several electrical systems stopped working

Post by fako2806 » Wed Nov 30, 2016 10:45 pm

Hello everyone, i've got a huuuuge problem with my 1989, 70kw (95hp) Volvo 480ES.


Over night, the slowest speed of the front wipers, the rear wipers (except the cleaning function), the seatbelt-warning-indicator, the rear window and door mirror heating, the warning flashers, the headlight flasher and the direction indicators broke down.
I have absolutely no idea why all these different functions stopped working at the sime time.
I already tried to use the CEM-selfdiagnose but it didn't work although I followed the instructions correctly. I also changed the direction indicator fuse but without any result.

I'm not really a good technician and i won't be able to fix too complicated stuff by myself...

I hope someone here is able to help me, or has at least an idea what could be the problem. Driving on the Autobahn without indicators is quite dangerous and I need a result soon :boom:

Thank you guys!

Martin Mc
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Re: Several electrical systems stopped working

Post by Martin Mc » Wed Nov 30, 2016 11:12 pm

It sounds like a relay has failed, or perhaps more than one.

The good news is that relays are easy to replace, the main ones being located under the hood / bonnet underneath the triangular cover on the left hand side of the engine bay / scuttle, on the opposite side from the air intake for the cabin fan.A quick look in there should give you some clues, and it is always worthwhile getting to know what is easy to access on our cars, as their age now means we are as well qualified as any mechanic to diagnose problems.

Good luck!

Martin
1991 ES White / 1995 ES Red / 1995 ES Red / 1994 S Black / 1995 Celebration Red / 1994 S Paris Blue / 1995 Celebration (again!) Red - Currently free of all extramarital cars, wrench-loose and fancy free :)

Ade
Can tell where the 480 was built
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Re: Several electrical systems stopped working

Post by Ade » Thu Dec 01, 2016 7:08 am

Aren't all those things controlled by the CEM rather than having relays in the box in the scuttle by the wiper motor?

When you say headlight flash, do you mean that the full beam doesn't work in the pop ups or the aux lights don't flash as they should. If it's aux lights not flashing then that's CEM related, only the main headlights are done with a relay in the box under the bonnet as described by martin. CEM also does indicators and wipers, does sound to me like a CEM issue.
O.C. 480 D.

Martin Mc
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Re: Several electrical systems stopped working

Post by Martin Mc » Thu Dec 01, 2016 7:32 am

That is a good point Ade, and I think similar issues have recently been raised and resolved on here too - see http://www.volvo-480-europe.org/forum/v ... EM#p209719

A simple tip I picked up during my own engine re-commissioning was to disconnect the battery (completely) for at least 20 minutes, which allows the CEM to reset. If you try this, best case is you only lose 20 minutes, worst case if the problem persists being that you have to press on for another solution.

CEM units are readily available for the 480 / 400 series on eBay, by the way, for around £25.

Good luck!

Martin
1991 ES White / 1995 ES Red / 1995 ES Red / 1994 S Black / 1995 Celebration Red / 1994 S Paris Blue / 1995 Celebration (again!) Red - Currently free of all extramarital cars, wrench-loose and fancy free :)

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dcwalker
480 Is my middle name
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Location: York

Re: Several electrical systems stopped working

Post by dcwalker » Thu Dec 01, 2016 9:14 am

I'd agree with Ade & Martin. CEM controls all those functions and this sounds like a major failure.

Disconnecting the battery for a time might work; also check the connections to the CEM - are they all good and tight? Given how these cars leak, has water got onto it? Might just need removing and drying out...

If you do need to find a new CEM just be aware that there were three versions: as a 1989 yours will either be 1 or 2 (it will say on it).

Good luck!

David
Current: 1994 480 GT, 1996 460 CD & 1997 440 LE with lots of optional extras & 2007 V50 SE Sport
Previous: Celebration 331 (re-homed with Richard S), Celebration 467 (returned to Martin Mc); Celebration 346 (re-homed with Alan480); Celebration 269 (scrapped abandoned project), Celebration 73 (sold on after 6 years), 1992 ES, 1988 ES - and numerous other non-480 Volvos!

Alan 480
480 Is my middle name
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Location: Aberdeen

Re: Several electrical systems stopped working

Post by Alan 480 » Thu Dec 01, 2016 12:55 pm

I had a similar issue with previous 480.

CEM module (The plastic one on LEFT side of car) ie drivers side if a LHD was half full of water :(

I removed it dried it in airing cupboard. cut the corner off to let any future water drain out and put an extra bit of plastic to cover it.

all was well until sold it, no more issues :D
Alan

480 ES 2litre 'Celebration' ? , C30 1.8ES, SS1

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brinkie
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Re: Several electrical systems stopped working

Post by brinkie » Thu Dec 01, 2016 12:57 pm

All evidence points to a faulty CEM. You could try and check the fuses first (all of them!). If they are all OK, take the CEM out (left hand side of the interior, see the FAQ on this web site) and open the box. Sometimes it helps by just cleaning everything including the contacts. The early CEMs are all suffering from a design fault, they have connectors on top (allowing leaking water along the cable loom to enter the CEM) and the box is almost closed, so water becomes trapped in the box.

A 1989 480 ES has a CEM-1, with self-diagnose. The nomenclature of CEM is not very logical, you have a CEM with -00 in the Hella part number which is without self diagnose and -1 has self diagnose by connecting two plugs together, hidden in the cable loom under the left hand side footwell. From 1991 onwards (Phase 2), a CEM-III is used with self diagnose using in the plug under the hood. The CEM-0 and -1 are almost identical, while a CEM-III is a different unit.

This is the CEM you're looking for, Hella 5 DK 004 696-01 (Volvo 3 434 379)
Image

Unfortunately, I don't have a CEM in my box of spares anymore, I have donated mine to a fellow 480 driver and electronics enthusiast to fix his faulty CEM. However, if you cannot get hold of a replacement CEM, I know someone who has spares (he asks € 50 for a CEM if I am not mistaken)
Robert.

Present cars: 1994 Volvo 480 GT 2.0i, 1999 Volvo S70 2.5 Europa, 2010 Volvo V70 2.0F Momentum

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