Technical Dim rear side light (led)

Currently reading:
Technical Dim rear side light (led)

Joined
Oct 1, 2017
Messages
7,227
Points
2,256
Location
Edinburgh Scotland
Feeling quite pleased with myself having completed a major service and cam belt (Inc water pump) on my boy's 2012 Punto. The hardest thing was getting the rear drums off due to humongous ridges on the inside of the drums. Judging from the dust accumulation it's been years, if ever, since they were removed!

Just to keep me in my place though, as I was doing my final checks - operation of lights, lubing door, bonnet and boot hinges and locks, wiper blade condition, recording tyre depths, etc. Noticed the NSR tail light was out. Removed the light unit to change the bulb only to find its an LED! Did a search on the Forum only to find its a known failure. In fact, when you look at it in the dark, the light is actually on, just very dim! I read that the problem is down to a control board which is a sealed integral part of the light unit?

From what I'm reading it looks like a new (or used) light unit is the (expensive) solution. Don't fancy the idea of an unknown condition used unit! Luckily his MOT is not due for some time and it'll be just jolly bad luck if he gets caught out for is in these days of long daylight hours but it will have to be sorted. Anyone know if there is any way to "fix" it? Or are we just as well to bite the bullet and buy a new one. (Shop4parts) seems to do them for a bit over £60.

Thanks for any advice offered.
Jock
 
Hi folks, deathly silence going on here! Of course it may just be dead batteries in my hearing aids again! Good excuse when I want to pretended I didn't hear Mrs Jock!

But seriously, anyone know of a cheaper way round this? Just rang "Uncle Arnold" our local Fiat main dealer, circa £125 for one light unit!!!!! Shop4parts is looking good at £66.70 (excluding Vat) but still a lot of money my boy can't afford so Dad will probably have to fund it and a cheaper solution would be good. Don't want to go used though.

So. Anyone out there able to advise?
Thanks
Jock
 
Diodes… die old, but they do !

Sorry but so far I've never seen one of those cluster open so I can't advise about a possible repair procedure, but there is certainly some way to hack it…

BRs, Bernie
 
Diodes… die old, but they do !

Sorry but so far I've never seen one of those cluster open so I can't advise about a possible repair procedure, but there is certainly some way to hack it…

BRs, Bernie
Thanks Bernie. Maybe I need an electronics chap, not a mechanic? The chap who lives 2 doors up the street from me is a computer boffin who is always fiddling with electronic devices. His living room is half living room half electronics workshop. Don't know how his family live with it, but a very handy chap to know! I occasionally help him with car "stuff" and he advises me when I mess up my computer! - Think I'll have a wee chat with him.

I'd still be very interested in any input from other forum contributors though.
Regards
Jock
 
By the way, the car is just 6 years old with 44,000 miles on it. My boy has owned it for the last two years and does a minimum of night driving. From what I read of them LEDs should last a lot longer than that so I'm putting my money on the controlling circuit board. Just don't know where it is, how to get at it or what to do with it if I do find it! However if I can access it I may be able to get it repaired.
 
Hi guys. I have the same issue! I noticed it today. Few months ago my letf tail light stopped work completely. I dismounted it, cleaned connectors anf found some electronic board inside, but cannot reach, it was sealed inside :-( Anyway when I mounted all back it started to work ok. But today I noticed that this tail light is dimmed than opposite side :-(

Tomorrow I'll remove it and make some pictures whats inside
 

Attachments

  • 20191116_183335.jpg
    20191116_183335.jpg
    663.9 KB · Views: 23
Last edited:
Yes, I noticed moisture in both lights from time to time. I found info that moisture is common problem without solution. Anyway tomorrow I'll also measure voltage on left side and right side connectors
 
Last edited:
So solved. Today I cleaned it, checked connectors and mouted light back...and it works ok :) I dont know what caused it, but most probably that moisture because last few days was raining + fog
 
I think that solution could be replacing bulbs inside lights for new one and seal whole light completely with black silicon. Can be problem next time to dismantle, but cutting silicon is easy...and because there are new bulbs, it can hold next 5 years... what do you think?
 
Oh dear, I need to eat a large slice of "humble pie" here. You may have noticed I often invite people to update their threads and give us the outcome of their problem. I sorted out the problem on my boy's Punto shortly after my last post in this thread but have failed to update! - sharp slap to wrist!

Whilst trying to sort it out I did a lot of googling, you tubing and searching our forum and the common theme running through it all seemed to be moisture interfering with that circuit board. I also learned that in late 2012 early 2013 a modification of some sort was made to the unit specifically to address this. So if you are buying a new unit now it should incorporate these changes - probably also something to watch out for if buying a used unit as you wouldn't want to end up with one of the earlier ones? I came across several recommendations that you attempt to dry out the old unit, and people were reporting success with this, so I pinched Mrs Jock's hair dryer (shh, she doesn't know) and ran it at medium heat into the unit for about 5 minutes before putting it in the airing cupboard overnight - where the hot water cylinder keeps things really cosy - before putting it back on the car next day. I was especially careful to be sure the foam seals were intact and I thought I had "cracked" the problem because the light worked perfectly when I tested it. Unfortunately, about a fortnight later, my boy rang me up to say that it was back to it's "old tricks". I gave in at that and ordered one up from the guys at Shop4parts. It took moments to swap it over the next time we were round at my boy's house and it's worked perfectly ever since.

For years we managed absolutely fine with bulbs. Ok, very occasionally, we needed to fit new ones and sometimes give the fitting a little rub with some emery to get a clean connection but all this was at minimal cost. LEDs look "trendy" (some might say) but, in my opinion, are just not worth the cost.

As a matter of interest I then dismantled the old one - effectively destroying some of the plastic (it could have probably been glued back together though) and I took it round to my "electronics" friend for his opinion. He kept it overnight and when I saw him the next evening he told me that electronically it was working fine BUT, there were traces of verdigris and corrosion in several places on the board. His opinion was that this was becoming conductive when moisture was forming inside the unit and causing partial shorts and it was this which was causing the malfunction. This seems very logical and would explain why my drying out procedure was temporarily successful.

So, if this happens to you what is the best thing to do? I think the number one thing is to check all seals to stop water getting in in the first place. The lamp unit is very easy to remove and perhaps it might be a good idea to just pop them both off and have a look at the seals before any defect occurs? Maybe a smear of Vaseline around these seals might be a good idea? (the only trouble with doing this is you can't then subsequently use an adhesive product if you continue to have problems and want to try a more "drastic" solution - suggestions anyone?) Next I think it's worth trying the drying out procedure as it will probably work if you don't yet have any contamination on the board. If all this come to nowt then you are into replacing the unit but be careful not to buy a pre '13 unit. Personally I would just bite the bullet and buy a new one from a discounting source.

If any one has anything to add please do pitch in because, of course, the boy's O/S unit is still the original and we are now wondering if it's going to go the same way one day. Or, now that I've carefully checked the seals, maybe it won't?
 
Last edited:
So solved. Today I cleaned it, checked connectors and mouted light back...and it works ok :) I dont know what caused it, but most probably that moisture because last few days was raining + fog

Thanks for the update Rado77, BTW Jock, I can't remember how you fixed it on your boy's car ...


BRs, Bernie
 
D'you know, We've managed absolutely fine with bulbs for so many years and they've become much more robust and long lived as developments have taken place. If something went wrong it was usually either the filament failing or a poor connection somewhere which was invariably easy to sort with a wee rub with a bit of emery and a light coating of vaseline to stop corrosion. Latterly developments with reflectors made bulbs very effective indeed and some manufacturers have produced very attractive displays. The big thing was that when a light failed it was usually very cheap to sort out.

Now we have LEDs in tail light and DRLs on the majority of vehicles and they are horrendously expensive to replace as, usually, it entails replacing the entire unit. (Why the whole unit? I ask myself) I know the argument is that these LEDs are much more long lived but they still seem to fail and they involve additional electronics which can fail also, of course, damage - accidents etc - still occurs which can mean replacement. Sorry folks - all you who like "blingy" things - but I think this is a backward step. Bring back bulbs I say!
 
Hi guys, looks that moisture isnt only one problem. There must be really biger hole (ans I know that its directly in foam seal which seals main connector to whole light), and also dust is going there. But not directly from outside, but from space under body panel from where main cable is coming. Looks that problematic is that foam-seal...I dont know how to name it...You can see dust particles inside. So solution - modify that foam seal somehow + seal hole in body from where is main cable coming with tape. But that foam seal was wet, so it's soaking moisture, and thats bad too. Maybe creating own seal from rubber...
 

Attachments

  • 20191117_152707.jpg
    20191117_152707.jpg
    668.9 KB · Views: 64
Last edited:
It would be interesting to see what ages the MANY puntos.. that have reported the faults are.

I must admit my 2012 does get steamy looking rear lenses..
but I Beleve it has worked fine.

Somebody reported seeing a @2014 with the colored Grande spec lights.

No doubt these were cheaper to buy than just the 1 LED unit Fix..
 
Last edited:
Once I get this issue again, I'll completely seal lights from back side with black silicone (especialy joint between "glass" and plastic part of light) + create own main seal from rubber (around main connector). This should solve whole issue forever
 
Last edited:
There are foam sheets that exist from which you can cut (cisors) fairly complicated shapes that would fit almost any situation. Available in different thickness to accomodate the gap you need to fill. Just be sure to order the "closed cells" type ...

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
 
Back
Top