Technical fiat stilo rear light total failure

[Gidian]

Hi guys, hoping someone can help. A couple of weeks ago I got a bulb failure warning light saying my rear left stop, indicator and fog light had failed. Checked the lights and they were fine. This has happened before and a scrub of the connectors would fix the problem, so I wasnt too worried when the problem started again until yesterday when it said my right lights had failed, and after checking to see if they were working, discovered that neither of my rear lights are working.
So i'm at a loss. I thought it couldve been a loose earth wire but that wouldnt affect both rear lights would it?
Any help would be greatly appreciated. Thanks

 

[Maigretnz]

Use a contact cleaner on the cluster plug or better look at this post I started.

https://www.fiatforum.com/stilo/325648-cleaning-contacts.html

 

[Gidian]

Use a contact cleaner on the cluster plug or better look at this post I started.

https://www.fiatforum.com/stilo/325648-cleaning-contacts.html

Thanks for your reply but I don't think this is a simple issue as loose cluster connectors. As I said I have cleaned up the connectors before when I started getting the bulb failure warning light. But it actually only worked temporarily until I decided to just replace the rear cluster completely. The issue in having is that neither lights are working. Left and right rear, which makes me think the issue isnt dirty light cluster connectors

 

[saw]

so you havent tried it then?

 

[Gidian]

so you havent tried it then?

Yeah, it was the first thing I tried. I've cleaned the connectors with electrical contact cleaner and a wire brush, cleaned the earths incase of corrosion but they were completely clean as well. I think the boot brake light still works but that's it.

 

[Maigretnz]

I found regular contact cleaner wasn't sufficient for a permanent fix. (you did say it fixed it temporarily)
Corrosion was the problem with mine. I don't recommend aggressive methods such as sandpaper etc. Metal polish followed by contact cleaner worked but the kit I gave a link to gently removes corrosion and prevents it coming back.

 

[Gidian]

Well today after giving my lights a more thorough going over, checking for any worn bulbs I noticed that the connector that plugs into the light cluster was burned. The black wire has actually melted the plastic of the connector. Does anyone know which bulb the black wife is responsible for and if replacing the bulbs would rectify the issue?
On another note, ever since I've had this issue, I noticed that with my wipers on, my rear wiper stays on. Even though I haven't twisted the switch for it to even be on! Could this be related?
Thanks for the help

 

[Peat]

From memory the BLACK wire is EARTH/Ground return and if traced should go to either C30 or C31

 

[Davren]

Black wire is the earth wire.

A faulty rear earth may cause problems with the rear wiper, however the rear wiper is designed to come on when you switch the front wipers on and select reverse gear.
.

 

[Gidian]

Black wire is the earth wire.

A faulty rear earth may cause problems with the rear wiper, however the rear wiper is designed to come on when you switch the front wipers on and select reverse gear.
.

Thanks, I suspect the earth is probably the culprit here then. I was definitely driving forward when the rear wiper kept coming on After giving the lights a thorough scrub last night, the right side lit straight up. Which surprised me as they weren't really dirty, all I did was wipe down the circuit board sorta thing, and had already previously cleaned the connectors so I still can't see why they wouldn't have worked before. Left side however still wouldn't work. So I got some pliers and bent the tooth that the earth connects to and presto! Lights are working. Well almost. Driving to work this morning when 'beep beep beep bub failure rear left indicator'. So atleast I know the problem, just not sure how to fix it now. The earth cable looks like it's burned through the plastic connector and it's looking abit crispy, so probably not getting a good connection. Why it's burned the plastic, I can't work out. Would knackered bulbs cause it? Just general wear and tear?

 

[Gidian]

From memory the BLACK wire is EARTH/Ground return and if traced should go to either C30 or C31

Cheers Peat. Are c30 and c31 fuses, and if these are replaced would that fix the issue?

 

[Peat]

No. They are earth points on the inner wing on the 3dr. Black boxes.

 

[Davren]

The earth cable looks like it's burned through the plastic connector and it's looking abit crispy, so probably not getting a good connection. Why it's burned the plastic, I can't work out. Would knackered bulbs cause it? Just general wear and tear?

If the connector was not making good contact, it could arc and cause localised heating at the connection. Ths can cause the connection to overheat and the plastic connector holder to burn or melt. Only solution would be to replace the connector holder, but they are not available seperately from Fiat.

Ask a breakers if they will cut off a sell you just the connector holder.
.