The dash display spends most of its time completely off/dark. No speedo, tacho, gauges, no lights showing other than heated screen and parking sensor switches. Radio display off, heater display off, indicator click sounds off, seatbelt warning sound off. Other than that everything works fine - heater, radio, all lights and functions.  I can use a sat nav as a speedo. However I will be stuffed come next MOT if I can't sort it. I've owned the car from new and am reluctant to scrap it just for a dash fault. Occasionally the whole display lights up and just as quickly goes blank. Sometimes it stays on for a short journey, but goes off when re-started.

Local independent mechanic did some diagnostic test, said it was not the BCM, said he couldn't find a fault, and advised me to replace the radio as it was the only place the 'can-bus' wires could short out causing my problem. I'm a bit doubtful. I may disconnect the radio to see if that has any effect.

Lots of stuff online about dry solder on dash cluster. Fairly cheap fix via ebay. That may be next on the to-do list after radio disconnect.  However, no amount of thumping the dash changed anything. And, would this also cause the heater / radio displays to go dark whilst they work fine in 'dark' mode?

There was a similar post in the S-max section a long time ago but no solution. 

Does anyone have experience of a similar problem that has been fixed? 

There's a chance it's the cluster, the only way to find out is to take it out and get it re-soldered.

@rd457 will help you

Is it the type pictured below? This type does suffer from the common cracked solder joints problem. The variant with the tall screen depicted here also suffers from a secondary needle movement issue that's resolved with some solder joint reflow work.

The fact that nothing changes when bashing the dash doesn't really prove anything, conversely it can give positive confirmation, but a lack of change really proves nothing.

Is it likely to be causing the radio issues? Hard to say, but another strong possibility is the ignition switch. I had a customer the other day with a Mk2.5 Focus who sent me their cluster, I repaired the cracked connector joints, sent it back, they replied saying that it had cured a bunch of errors but there was still delayed movement of gauge needles after starting and the radio coming on was also delayed. I suggested the ignition switch and replacing it cured these remaining problems.

The radio being faulty is also a reasonable possibility. No harm in seeing what happens with it unplugged.

Hi, sorry for the late response.

Yes that is the same cluster as mine.

These can be re-soldered?

Do they need to be re-programmed?

Yes, here's my service, no reprogramming necessary: https://www.ebay.co.uk/itm/314393033915

Hi

Thanks for that.

I'll have to wait for a school holiday before I send you the cluster as I'm using the car every day with sat nav for speedo. 

ps - 'dashboard bashing changing anything' - I'd read on here that hitting the top of the dash would temporarily re-activate the display if dry-solder joints were to blame. In my case, that wasn't the case. 

Regards,

Chris

Conversely, if I get the part no. from the existing IC and buy a 2nd hand IC from a scrappy on Ebay, apart from the risk that it may too have solder problems, will the replacement IC need to be re-programmed. And if so, is this possible?

Thanks, again,

Chris.

3 hours ago, ChrisWhitley said:

ps - 'dashboard bashing changing anything' - I'd read on here that hitting the top of the dash would temporarily re-activate the display if dry-solder joints were to blame. In my case, that wasn't the case.

In some cases it will cause a slight movement bringing the two sides of the cracks of one or more joints back into contact and thus you'll see a difference, confirming that the joints are cracked and part of the problem. No change upon bashing the dash doesn't prove anything, in that case either the fault is unrelated to any cracks in the IC connector joints, or the bash just didn't happen to do as just described (in which case pulling the IC out and wiggling the connector instead could be tried).

2 hours ago, ChrisWhitley said:

Conversely, if I get the part no. from the existing IC and buy a 2nd hand IC from a scrappy on Ebay, apart from the risk that it may too have solder problems, will the replacement IC need to be re-programmed. And if so, is this possible?

It would need to be reprogrammed probably including key reprogramming which would have to be done with the entire car or via a remote computer session. I don't do any of this stuff. There's also the issue that some mileage correction solutions can only increase the value.

Ok thanks,

1. I'll disconnect radio per diagnosis.

2. Get IC out and wiggle connector.

3. Depending on 1 & 2 above, send it for re-solder.

Regards,

Chris