Technical Maybelline has thrown a hissy fit

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Technical Maybelline has thrown a hissy fit

The wrapping stops as it touches the grommet.
If it is a repair, it looks like it was done in the factory.

As far as I know, Rosa has had nothing done to her from new. She had only done 13,700miles when we bought her shortly after her first MOT. We have the service records ........... not that there's much to read.
 
Does that actually go through the grommit or is it just a wrap that holds the bundle together in the boot lid?

The latter, although the end of the grommet may just overlap the wrapped part of the harness. It's common practice for car makers to wrap the harness with felt tape in areas where it might vibrate against the bodyshell or other panels to keep the rattles down and reduce the chafing risk.

It isn't always enough; hence the recall on some later 500's for the wiring near the steering column.

In this case, it may make the problem worse, as the cables usually seems to fail just after the wrapped portion.


There you go!

Keep going Mick, you haven't finished unwrapping the parcel yet.

Push the grommet back along the wrapped cable (compressing the grommet), then carefully unwrap the end of the felt tape.

It's easy enough to reassemble if all is well.

Another picture (double click to enlarge it). You can see where the felt tape wrapping finishes; also the surface corrosion on the thickest broken wire isn't fresh & shows the progressive nature of this fault.

The thick black pipe carries the rear screenwash fluid; others have reported this pipe also breaks with repeated use of the hatch. Carrying wiring + electrolyte through the same fragile harness makes this a triumph of p*ss-poor design.

Enclosing the whole thing in a robust, flexible grommet (which is much more durable than what's inside it) practically guarantees noone will find this fault until something actually breaks.

I wonder also if it's possible to do some preventative maintenance on the loom early on prior to failure,ie, lubricate cables now and again to keep supple etc? And yes, NOT with WD40 obviously but there must be some rubber or plastic lubes that would do the trick.

Unfortunately not. The copper wire will work harden when repeatedly bent and evetually fail.

The only two options which will last in the long term are to splice in some new wires which are designed to cope with the repetitive flexing, or to weld the hatchback shut.

I'll bet most main dealer repairs don't go the distance.
 

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Keep going Mick, you haven't finished unwrapping the parcel yet.
Oh well.:eek:

Chucking it down with rain out there, so I'll leave it for the time being.

However, from what I read now on here, the wires ought to be plainly on display without any wrapping at all! ;) No point leaving problems to fester away out of sight and out of mind.

We used to have an AppleMac iBook, and they were plagued with failing wires as they left the main body and up into the display via the hinges. They were just plain insulated wires inside a plastic flexible tube. Eventually, they break. I stripped ours down and spliced in new cables. They weren't neat, but they worked ok.

We now have a MacBook and a MacBook Air, and I believe they have some sort of ribbon cable to link the body to the lid. My MacBook is nearly 9 years old and still works well. The iBook didn't see it's fourth birthday before it broke.

Our Renault Clio is fourteen years old and the hatch is used frequently. Mrs Mick F is at work now - she drives the Clio to work and back. I must have a gander at the system that Renault use and see how it differs from Fiat500's. I'll look later .......... if it stops raining.

Regards,
Mick.
 
I recall there is a good quality replacement loom section available from Germany I think? Every time I open my boot I'm conscious of the loom but I dont use it that often, I'm also gentle with the door handle in the hope I can extend its life too! Is it possible to lube the door hinge in situ or is there any point? My car is 2014 so maybe they addressed the issue - wishful thinking I suppose!
 
Here's the way Renault did it with our 2001 Clio.
There are two of them and equally tight and kinked as a 500.

Mick.
 

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I recall there is a good quality replacement loom section available from Germany I think?

There certainly is - someone else here reported using it successfully.

Is it possible to lube the door hinge in situ or is there any point?

Pointing a fine nozzled can containing a rubber-safe silicone spray into the approriate part of the handle might help and shouldn't hurt, but if you want to lubricate it properly with a dry graphite hinge lubricant, you'll need to take off the door card.
 
Here's the way Renault did it with our 2001 Clio.
There are two of them and equally tight and kinked as a 500.

Mick.

Actually Renault have come up with a much better design.

Look carefully at your Clio and you'll see those wires run in what is essentially a straight line; when the hatch opens & closes, the wires are in torsion (they twist, but stay straight). That twist is distributed along the whole length of the connection and will be well within the elastic limit of the cable. They should last the life of the car.

On the 500, the wires don't run in a straight line, and when you open & close the tailgate, they bend rather than twist. Each time you move the hatch, they are bent across only a small part of the connection. It's the repeated bending across a relatively sharp edge that is causing them to fail.

It's a piece of poor design which goes all the way back to basic engineering principles.
 
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Right, here's what Haynes says.

Lock is just a simple switched motor (from the body control unit):
White is switched power
Black/Pink is GND

Rear wiper motor has three wires (Ground, sense and power); controlled by the BCU:
Black/Green is power
Black/Purple is feedback
Black is GND

Heated rear windscreen is switched from the BCU
Brown/White is Power
Black is GND

Number plate lights are surprisingly power separately from the BCU:
Yellow/Grey and Brown/Green are power
Black is GND

I think that's everything?

There's good and bad news there I think as far as JR is concerned- there's no CAN bus whatsover there and everything appears to be +12V/0V, so it seems unlikely that you've badly fried the BCU. Equally there's nothing really there that makes me go "AHA! If that's cut out the BCU will stop doing some things as it doesn't have a critical feedback", so there's no immediate explanation.

Have you checked it's nothing stupid like a fuse blowing and taking down a system/sensor?

Was interested to see each system has a dedicated ground wire, but when you think about it that makes perfect sense otherwise getting a good ground through the hinge would be a nightmare.

I'd urge people to buy a Haynes- whilst they're not perfect they're rather inexpensive and, for a modern car, absolutely chock full of little bits of info that are great for jobs like this.
 
I also thought about this possiblity whilst driving home - opening the driver's door was the other thing I did when visiting my friends.

First pictures at the end of this post.

We've seen similar images of the wiring before, but look carefully at the grommet. It's completely intact and free of splits or breaks - there's simply no way you can know what's going on inside from an external inspection (I put a piece of white card behind it to get a better photo).

No point going anywhere with diagnostics or speculation until the hardware's fixed. I've got a lot on just now & the Panda works just fine, so I may park both car and problem for awhile. The battery is staying disconnected.

Whatever, owners of 500's out of warranty should be aware that they could land themselves an unexpected problem (& large bill, depending on how you go about fixing it), just by opening the rear hatch. :mad:

I'll bet any money you like that if you took a car with these dashboard issues to any main dealer, the first thing they'd do is put the car onto diagnostics.

My current advice to any 500 owner with an electrial problem is to peel back the grommet (you only need peel back the end that's attached to the tailgate, since that's where the breaks happen) and inspect these cables before doing anything else. Actually I'd go further and advise all 500 owners to do this check regularly, even if the car is otherwise well. A small dab of silicone grease or a quick spray of rubber lubricant on the grommet will make it easier to remove & replace the end. DO NOT USE WD40 - it will likely attack both wiring & grommet & make a bad situation worse.

If yours looks like mine, I'd suggest you don't attempt to drive, or even start the car. Just unclip the battery quick-release terminal, & call a mobile auto sparky if you can't or don't want to fix it yourself.



There's some very light gauge cables in there (including the broken one) which surely can only be used for carrying control signals.
Condolences,hope you can get that mess sorted to get her back on the road ,certainly was a really bad design error unfortunately not spotted by the testers,when you first started writing about warning lights i thought another failing ageing battery(wrong) ,good luck and hope you have her back on the road soon .
 
Condolences,hope you can get that mess sorted to get her back on the road ,certainly was a really bad design error unfortunately not spotted by the testers,when you first started writing about warning lights i thought another failing ageing battery(wrong) ,good luck and hope you have her back on the road soon .
testers are ytou joking me? even if the testers saw it they probably chose to ignore it = )
 
I think that's everything?

Thanks Zanes, that's a nice concise summary from the Haynes manual, and of course I've also got elearn to cross check against. The two heaviest wires must be for the HRW, and that ties in with your table.

I haven't started pulling fuses or going any further with the diagnosis; there doesn't seem much point until I've sorted out the hatch wiring. The car clearly isn't going anywhere until that's been done.

I'm quite busy at the moment, and fortunately I don't need the car right now, so it can wait its turn whilst I assemble the various bits of wire & connectors I'll need to do this.

For someone who needed the car every day and didn't know a soldering iron from a multimeter, this would likely be an expensive headache - there's no guarantee what might or might not be needed even after the physical wiring is sorted and it's almost certain to need either MES or Examiner to reset the electronics afterwards, so most independent garages & autosparkys likely couldn't fix this.

Right now I'm as puzzled as you are as to why this should have given the airbag ECU a headache, but all may be much clearer by the time it's all sorted. The BCU must monitor the current on these lines somehow, as it flags an error if the lights fail or the bulbs are out of spec.
 
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We had a numberplate light fault. It turned out to be a bulb dislodged and the holder out of its location. I clicked it all back together and all was well.

The Haynes manual seems to suggest that there are two power feeds and an earth. Fine, I'm sure they're correct.

BUT

When I fixed the fault, we had a the flashing odometer problem!

Therefore there's more to this than just power and ground.

Regards,
Mick.
 
When I fixed the fault, we had a the flashing odometer problem!

Therefore there's more to this than just power and ground.

Absolutely. It's also necessary to consider what's connected to the other end of these cables and in partcular the way the BCU obtains the information it needs to generate fault messages for the lighting & indicators & communicates this to the MFD.

Like almost all modern cars, the way in which the various electrical and electronic components and modules interconnect is complex. Diagnosing & repairing these sort of faults needs more than just a knowledge of ohm's law.

Diagnosis through software is only part of the solution and it's important to remember that the diagnostic equipment might not work correctly if there's a wiring fault that's causing a crossfeed, stray live or ground condition. A technician who relies on first putting a car with an issue like this onto examiner could easily be misled about the true cause and spend many hundreds of punds of your money replacing the wrong parts. Reading between the lines of past threads, I'm sure this has happened to several folks here already.

What I'd recommend now is that if you have any kind of electrical problem, checking this wiring should be the second thing you do, before attempting any other kind of computer-based diagnosis. The first thing you should do is disconnect the battery quick release. If there is a fault in this wiring, even just inspecting it could cause further electrical problems if the car is powered up.
 
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I haven't built up the courage to look at the wiring condition yet, but had a look to see if there is any wear on the grommet or hose. I know that isn't necessarily an indication of what's happening below but didn't expect to see this on the paintwork..........DSC_0008 (2).jpg
 
I haven't built up the courage to look at the wiring condition yet, but had a look to see if there is any wear on the grommet or hose. I know that isn't necessarily an indication of what's happening below but didn't expect to see this on the paintwork..........

The grommet will be the last bit to fail. It's absolutely no indication of what's going on underneath - mine was as unblemished as yours.

If you do inspect it further (and IMO it's worth doing), I suggest you unclip the battery quick release first - just in case. You'll have to reset the clock afterwards, but that's about it. The radio code is stored in the body computer, so you won't need that.
 
The grommet will be the last bit to fail. It's absolutely no indication of what's going on underneath - mine was as unblemished as yours.

If you do inspect it further (and IMO it's worth doing), I suggest you unclip the battery quick release first - just in case. You'll have to reset the clock afterwards, but that's about it. The radio code is stored in the body computer, so you won't need that.

Thanks for the tip. I needed to free up the boot handle (again!) today and checked the cables. Sure enough, the insulation has split on three cables - black, brown and purple ones but none broken. I've isolated the cables with insulating tape until I can get a permanent fix done.

Incidentally, has your paint been stripped down to the galvanizing too?
 
Incidentally, has your paint been stripped down to the galvanizing too?

Yes, this seems to be common to most 500's I've seen.

It wouldn't surprise me to find at least one wire with broken insulation if you were to peel back this grommet on any 500 over 2yrs old (n).
 
Yes, this seems to be common to most 500's I've seen.
Well, is this a tell-tale sign?

Could there possibly be a connection (if you pardon the pun) between wear of the paintwork and wear of the cables?

Not peeled back ours yet. I may do it during next week.
The paintwork on ours looks as good as new.

Thanks,
Mick.
 
Thanks for the tip. I needed to free up the boot handle (again!) today and checked the cables. Sure enough, the insulation has split on three cables - black, brown and purple ones but none broken. I've isolated the cables with insulating tape until I can get a permanent fix done.



Incidentally, has your paint been stripped down to the galvanizing too?


How old is your car gazz?
 
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