Reconnecting battery and clock/odo display

[crc_73]

I've been having electrical issue(s) with a 2002 Leon for some months now, but wondering about this...

If you've had the battery disconnected for a few days, and when you reconnect the battery, should the clock and odometer/trip counter displays come alive, without putting a key anywhere near the ignition?

I would have thought that they should, but they don't on this one. It's only when I put the key in and turn it to the first stop that the clock and odo/trip counters become displayed. All the other normal lights in the cluster (handbrake/airbag/ECU/etc.) come on and go out as normal when the key is moved to the first stop as well, as expected. When I go to remove the key, the clock and odo/trip counters then stay on when the key is switched to off and taken out (most of the time), which I believe is normal.

If the clock odo/trip counters should be coming on upon battery reconnect, but aren't, what might this fault be pointing to?

 

[Battoussai]

Yes, when you connect the battery the clock and odo/trip became right on. Both are always on even when you lock the car. I would check first the fuses and then the clocks connections on the back.

 

[crc_73]

Yes, when you connect the battery the clock and odo/trip became right on. Both are always on even when you lock the car. I would check first the fuses and then the clocks connections on the back.

Thanks for the confirmation, much appreciated. So it's as I thought it should be.

I have the Haynes Mk4 Golf book, so I'll have a look at the circuits, and see what fuses are involved, but the ones at the side of the dash/door were ok when I checked them some months ago, when I had the same issue.

And I have had the instrument cluster out and dismantled, so many times that I haven't bothered to put the needles back on until I think I have it sorted (if I get it sorted). I did find 6 or 7 pins on each of the 30-pin connectors to have fractured solder points, so I reflowed all of them, added some solder as well, and it seems to have cured the cluster light ghosting/flickering that it used to have, but this problem with the clock and odo/trip counter persists. The funny thing is that 9 times out of ten, the clock/odo/trip displays stay on when I remove the key, but that one time they disappear, I end up with an airbag light, so it's like there is a disconnect between the ECU/cluster/battery via something else, maybe a relay or something else solid state that just flakes out now and again? I can clear the airbag light, and it will stay off, until that 1 time out of 10 that the clock/odo/trip displays disappear when the ignition is switched off.

Or maybe I have a bone fide intermittent airbag problem?

Other work I've done is to clean all the grounds in the engine bay, under the battery tray, under the windscreen gutter, had a look in the ECU (no sign of water damage in there), have replaced the ignition switch as well.

I've ordered a second-hand cluster to do some troubleshooting, so it might help rule out some other possibilities for the source of the fault.

If anyone has any suggestions of things to look at based on the above, I'd appreciate it.

 

[Battoussai]

Ok, good work you have done there. I already had a airbag light on and it was the inner flat cable round thing that connects the airbag to the plug. Fixed the airbag light for me, but I used a VCDS program to discover it.

Part number 1J0959653 (European)

Also, see if the earth cable (mine is brown) on the steering wheel frame is well connected.

 

[crc_73]

Just revisiting this, I managed to get a second-hand cluster, pretty much identical as far as stickers and codes on those stickers is concerned, and as soon as I have it in place, and reconnect the battery, I get the clock and odometer coming on as expected, unlike what was experiencing with the original cluster. So, already a difference, and hopefully a positive difference.

Anyway, with the "new" cluster, of course there are lights coming on (like engine and low oil pressure), but they might be from when they were in the other car. And of course the immobiliser is actvated, because I haven't reprogrammed that yet. car will start, but will conk out after a couple of seconds. I don't seem to have an airbag light though, but there are probably other things I need to do first. And of course, the odometer is much lower, by about 60k miles.

Since getting the cluster, I also ordered a vag-tacho cable, as from looking around, I will need that to change the odo, but I'm still learning.

So I'm wondering, from here, what's the best way to proceed in order? Are there codes I need to get off the old cluster, and change to the "new" cluster?