Hi all, I'm new here and would appreciate some advice on this issue.

 

I recently got my father's Fabia Classic 2003 1.2 HTP 54 which has only done 28K miles. It's started to develop the problem of showing the power steering light occasionally, however, from what I can tell only becomes hard to steer when reversing. I've read it's quite a common problem and that it could be caused by the power steering angle sensor?

 

The bigger, more annoying issue for me is that the backlighting to the clock and bottom half of speedometer remains on all of the time which drains my battery overnight. When I drive I also get a very faint flickering of the seatbelt light and check engine light. I've read that this flickering and lighting issue could too be an issue with the power steering sensor.

 

Currently, I've resorted to pulling fuse1 which is responsible for the lighting Instrument Cluster which prevents this parasitic draw.

 

The battery is only a year old and reads 12.5 volts and 14 volts when running, so the alternator is fine.

 

I've checked the current when the engine is off with my multimeter on the 10A setting and it reads 0 with fuse 1 out, however, when putting the fuse back in the draw jumps all over the place from .1 to around .14. This indicates a short in the wiring for the Instrument Cluster lights?

 

I do a lot of reading and do enjoy cars but I'm quite new to doing repair work myself, so please be patient. Thanks in advance.

Here's a picture of the constant backlighting of the instrument cluster that drains the battery.

I'll drag a spare cluster PCB out of the shed after lunch and see if I can come up with any ideas for you. Fuse 1 takes a permanent power feed to the cluster so it's not as though that isn't being switched off correctly, because it should always be on.

May be worth taking out the cluster, unplugging the two electrical connectors and examining for moisture or evidence of corrosion?  Is the car generally dry internally, or moist?

 

I had a similar cluster flicker and faint glowing warning light in my polo TDI. It's a 'spare' car not often used and was damp from low use. Removing the cluster and putting it in the airing cupboard for two days sorted it and by increasing use/ventilation of the car it's not come back. I concluded it was damp causing the 'electrical leaks'.

4 minutes ago, Wino said:

I'll drag a spare cluster PCB out of the shed after lunch and see if I can come up with any ideas for you. Fuse 1 takes a permanent power feed to the cluster so it's not as though that isn't being switched off correctly, because it should always be on.

May be worth taking out the cluster, unplugging the two electrical connectors and examining for moisture or evidence of corrosion?  Is the car generally dry internally, or moist? 

 

 

Thanks, Wino and LB123 I appreciate it. The interior, in general, is dry with no damp spots that I've noticed, however, it was sitting unused for a few months before Christmas and developed a bit of mould which seems I've gotten rid of. I'll remove my cluster and try your suggestion LB123, fingers crossed. Do you think I should be concerned with the power steering light as I'm beginning to think these are separate issues?

I'd suggest trying to eliminate the cluster misbehaviour first, then see if any other problems remain.  Getting rid of battery drains is going to help everything electrical, even if the battery appears to have survived thus far.

Hi guys. I removed my instrument cluster and have had it in my house for the past two days and sadly when I put it in the lights continue to flash.

 

I'm currently going to keep fuse 1 disconnected. Are there any other suggestions? Thanks.

Edited 5 February, 20197 yr by ScottEnock

16 hours ago, ScottEnock said:

Are there any other suggestions?

 

See what happens if you re-instate fuse 1, and take out fuse 16 instead.  That's an ignition 12V feed, and shares a loom branch and connector on the instruments PCB (adjacent pins) with the feed that comes from fuse 1.  With ignition off it should not be supplying any current to the instrument cluster, but it would be interesting if removing the fuse does change what's going on.

Hi WIno. I just pulled fuse 16 with fuse 1 installed with the ignition off and the lights continue to flicker. So it seems to be isolated to fuse 1.

@ScottEnock

 

As expected TBH.

 

The general background lighting of all switches and displays is controlled via the dimmer switch thumbwheel near the headlight switch. Does the position of that thumbwheel make any difference to the 'rogue illumination'?

 

The output of that thumbwheel control doesn't connect directly to the instrument cluster as far as I can see.  It does connect into the 'Onboard Supply Control Unit' which must then communicate via the CANbus telling the instrument cluster what to do about its backlighting. So the cluster backlighting on/off/brightness seems to be generated locally on the cluster PCB depending on that CAN messaging, and I can't imagine there's a situation where that message would/should be "turn on the lower half of the backlighting in the instrument cluster in a dim, flickery way". I think they'd always behave 'as one' across the whole cluster in normal operation. So I think it has to be a problem on the instrument cluster circuit board.

 

Maybe take it out again, and remove the rear plastic cover so you can eyeball one side of the PCB? Look for evidence of moisture, or corrosion anywhere?

Edited 6 February, 20197 yr by Wino

Thanks for the info WIno. When I adjust the dimmer switch it does have an effect on the brightness of the flicker. I'll take the instrument cluster out and have a look at the PCB.

1 minute ago, ScottEnock said:

When I adjust the dimmer switch it does have an effect on the brightness of the flicker

Oh, that's interesting.  Even with the light switch itself being in the off position?

 

I can't quite recall, I'll have to check again if it affects it with the ignition off. Here's a picture of the PCB, it looks fine to me, I can't see any evidence of moisture, or corrosion.

Nothing obvious at first glance.

Staring at circuit diagram suggests to me that the dimmer control should not be powered, so shouldn't be able to be 'read' if the light switch is in the off position.

With the possible exception of when the indicator has been left in the up or down (parking light) position after switch off.

Edited 6 February, 20197 yr by Wino

8 minutes ago, ScottEnock said:

I can't quite recall, I'll have to check again if it affects it with the ignition off. Here's a picture of the PCB, it looks fine to me, I can't see any evidence of moisture, or corrosion.

 

I'm more interested in the flipside of that PCB, specifically the solder joints of that big green data cable connector.

That does have problems (cracked solder joints), on early cars especially, so well worth a look with the PCB completely removed from the front housing, then the film lifted up as much as poss.

 

Ignore the various circled and arrowed pins, they aren't specific to your issue here. In fact, I can't think of a mechanism whereby problems here could cause your problem, but that doesn't mean there isn't such a mechanism.  If any look cracked around the pins, reflow with a soldering iron and a little fresh solder.

As requested here's the underside, though the soldering looks fine.

 

For more detail, when I put the cluster back in the seatbelt and check engine light take a minute or so to start flickering but the clock light powers on straight away.

That actually looks like the top and bottom (left and right in photo) 6 pins have already been reflowed, maybe? Bulgier looking solder on those.

Hmm... I had to remove a white sticker with grey letters that looked like a warranty sticker when removing the outer plastic, so I assume I was the first one to open the instrument cluster since it was fitted by the factory?

Could just be a light/shade effect on the photo. It would be those end ones that would be most likely to be cracked though, as the weight of the loom vibrating is likely to waggle the outermost pins worst, I think (maybe?).

Some good news. I kept it by the radiator yesterday and today when I installed the cluster back in, the lights aren't appearing anymore that I can tell. I checked the amp draw and it's now pulling 0.02 - 0.03 amps on the 10 amp setting of my multimeter. The clock remains on constantly however and I suspect is the cause of the 0.02 draw. Is this normal for Fabias or is this still an issue? Thanks

Edited 7 February, 20197 yr by ScottEnock

Normal for clock and odo to stay 'showing' but not backlit.

 

That's great news. 20mA draw is normal.

1 hour ago, Wino said:

Normal for clock and odo to stay 'showing' but not backlit.

 

That's great news. 20mA draw is normal.

 

Perfect! Fingers crossed the problem doesn't come back. I really appreciate the help.

Well, looks like I spoke too soon. The light came back on Thursday evening. Is it possible that it's the wiring to the instrument cluster that's causing a short? When looking at people who had the power steering light come up they said it can cause electrical issues like this one. Any suggestions for going forward? I've taken the cluster back out and am keeping it by the radiator to see if that sorts it out.