Mk3 Cabrio Dash Clocks Dead

[OldMrToad]

Hi all

I'm hoping you can help me. During last years lockdown, I bought myself a Mk3 Cabriolet 2.0 Avantgarde (in an attempt to relive my youth when I had a Mk1 Cabriolet) nice low mileage (68k documented) and a Pink Floyd Edition (as a massive Floyd fan I was excited as you can imagine ! ) The plan was to basically restore it, and hang on to it forever.

It's a '95 on an 'M' Engine code 2E

Anyway, long story short, it's not been the trip down memory lane I was envisioning.

Lots of bits wrong with it, which we are working our way through (I'm sure I will be asking more stuff) and finding this site has made me a bit more optimistic.

The latest problem to manifest itself is that the speedo cluster appears to have completely died over the winter (car is garaged and covered) ... checked all the fuses, all ok. Fusebox appears to have been wet in the past, so replaced that. Cleaned up all the relays etc.

Cluster still dead, on the way, discovered that the headlight switch was faulty (no dimmer) so replaced that with a NOS part.

Cluster has been sent away to be 'repaired' as I read that they can just 'die' ... sent back, no faults found.

What is odd is that there appears to be 'some' power to the cluster, the lights dim with the dimmer on the headlight switch and the lights along the bottom (oil, brake etc) all light up when you turn the ignition on. However, the speedo, rev counter, digital mileage, digital clock, temperature and fuel gauge don't function at all.

I've checked the multipin plug to the back of the cluster and the other end of it is seated firmly in the new fusebox.

Cant find another cluster to try as it seems to be an odd part number that no one has ( 1H0 919 910C )

I've downloaded and printed the excellent info linked in another thread to the central electrics and will have a read through that tomorrow.

I've also read through 30 pages on the forum before posting this and no one seems to have a definitive answer or cure ?

I'm not particularly technical myself but I have a friend who is, but I really do seem to be monopolising his time recently with one thing after another with the car.

Any advice would be gratefully received.

Thanks in advance

Howard

[OldMrToad]

No one ? 

[Agreeable Slick]

You might be a little out of luck with info on here as the mk3 was not an overly popular model. However, you've mentioned that there was moisture in the fuse box, I'm wondering if perhaps this moisture has got to the spindles, and possibly caused them to corrode and jam up? I know on the old mk2 speedo cables there could be moisture in the cable that would make it's way up the cable and either break the cable internally after some time, or cause the needles to stick. Might be worth a look.

[itavaltalainen]

You could bench test the clocks.
Part number doesn't need to fully match, they can be reprogrammed for other cars, not easily but it's possible.

Might be able to help with sourcing or if reprogramming.

[OldMrToad]

Clocks have been sent back to Autotronics to confirm that they are indeed working.

I'll let you know when they come back. Hopefully next week.

I've looked closely at the white wire bundle that comes from the fusebox up to the clocks and its in great condition so I guess it's not the wires that are the problem. My friend will do a continuity test on each wire hopefully next week to confirm no breaks.

So, I guess it could be the inputs to the fuse box ? Where would I begin ?

Is there a common cause of these clocks not working (which isn't caused by actual clock failure itself ?) ... are there bad earths that are common , which ones to check ?

Where do the signals for the dash clocks come from, I mean the rev counter signal, the speedo signal, fuel gauge etc ? do they come from the ECU ? if the engine is running ok, i suppose that means the ECU is ok ? Are there any other hidden fuses that are tucked away anywhere ?

Someone mentioned ignition key switch before ? would that cause the clocks not to work ? the lights (brake, oil etc) along the bottom come on when you turn the key to position 1 ... does that suggest it's working ?