Technical Earth Issues

[SB1500]

Hello, I posted a while back about my rear wiper coming on when the brake pedal is pressed and the front wipers are set to on.

A few of you contacted me to say it was a simple enough fix, to clean the earth pin on the connectors for the rear light clusters. I did this, one side was a bit black but not too bad and a little off position. Fixed it and sprayed it with some contact cleaner. Did the same to the other side, out of good practice. It was clean and fine anyway though.

This didn’t fix the issue and I’ve been living with it for a few weeks.

Today, at Coleraine University I was admiring the reflection of the car in a window as I was about to depart and I noticed that when I push the brake in, the front headlight passenger indicator slowly lights up. Very strange.

This is a sign of some potentially imminent electrical mayhem..... from the top... where should I begin to investigate?

 

[DaveMcT]

You have some dirty earth connections on the wiring. Cars feed the live supply to "stuff" with the return via the bodyshell. Dirty connections where the loom connects will cause these sorts of trouble.

I can't tell you exaclty where to look but earths are bundled and bolted to the body shell.

 

[SB1500]

You have some dirty earth connections on the wiring. Cars feed the live supply to "stuff" with the return via the bodyshell. Dirty connections where the loom connects will cause these sorts of trouble.

I can't tell you exaclty where to look but earths are bundled and bolted to the body shell.

If I find the location of them all on the Fiat eLearn system and ensure every one is not crusty, dry and in tact should this solve it?

How many are we talking, approximately? Under 10, in the tens, in the hundreds?

 

[DaveMcT]

There are probably less than five earth points on the car. At least one will be inside the cabin and dry enough to never(?) rust. Wiring diagram will show where they are logically but not where they are physically.

Check the rear earth point(s) first. Fully clean the metal, coat with high solids copper grease and bolt down. Also check the wires into the crimp are not corroded. You might need to connect a new crimped eyelet to the earth wires. You can also run new earth wires from the light units. With good connections at each end, it's Job Done!

 

[SB1500]

There are probably less than five earth points on the car. At least one will be inside the cabin and dry enough to never(?) rust. Wiring diagram will show where they are logically but not where they are physically.

Check the rear earth point(s) first. Fully clean the metal, coat with high solids copper grease and bolt down. Also check the wires into the crimp are not corroded. You might need to connect a new crimped eyelet to the earth wires. You can also run new earth wires from the light units. With good connections at each end, it's Job Done!

Funnily, the light where the indicator is illuminating when the brake is pushed is the light I’ve never touched / had issues with

 

[koalar]

still sounds like a connection problem in one of the light clusters.


rear are the most common. The black contact will have been racking and the black oxides will need to be scratched off

 

[SB1500]

still sounds like a connection problem in one of the light clusters.





rear are the most common. The black contact will have been racking and the black oxides will need to be scratched off

I did clean off that middle black pin on the rear light cluster. Would removing that light and trying to use the system temporarily allow it to work normallY? with one back light detached and disconnected?

 

[koalar]

I did clean off that middle black pin on the rear light cluster. Would removing that light and trying to use the system temporarily allow it to work normallY? with one back light detached and disconnected?

I was thinking that myself, but don't know.


if there's someone to help you can normally spot the problem by finding a combination that makes a bulb dim


On mine the brake light would dim if the indicators were on. Which was the rear nearside connector. which had melted slightly and needed a pin bending slightly to make better contact.

 

[Wee Smurf]

Definitely sounds like an earthing issue. Hope you find it soon. Unusual that it's more than just the rear passenger cluster.

 

[SB1500]

Definitely sounds like an earthing issue. Hope you find it soon. Unusual that it's more than just the rear passenger cluster.

I must revisit that first. And show you guys photos of it. Perhaps I didn’t go a good enough job

 

[Wee Smurf]

Last time some Emery paper was used to scrape any crud off and then contact cleaner. Had to prise out a couple of pins to get at them properly.

 

[Kronkron]

I can't help, but my little panda has recently developed a similar problem, put the rear washer spray on and the front sprays as well ? Assume I have a similar fault or a fault in the stalk mechanism.

 

[SB1500]

I can't help, but my little panda has recently developed a similar problem, put the rear washer spray on and the front sprays as well ? Assume I have a similar fault or a fault in the stalk mechanism.

I do have a spare stalk for it! But isn’t removing the steering wheel needed? Hmm.

 

[SB1500]

Update: I got it fixed. Turns out, it IS related to the back light - as you’ve all said all along.

Upon closer inspection, there was black oxide. Scraped it out with a screwdriver, on the plug and connector. Didn’t seem like I was doing much, but it worked.

- no more indicator lighting up steady when brake is pushed
- no more rear wiper initiating when front wipers are set to an on mode and the brake is pressed
- no more fast blinking instrument cluster indicator blinkers


Question for me now is... will this last? Or will it be an every so often job?

 

[Wee Smurf]

Can't resist but say 'Told you so!' :nerner:

Mine has been fine for a couple of years now.

 

[steve w hebburn]

hi, strange what a bad earth will do i had similar rear light problems, when o/s rear indicator flashed, so did the tail light switched off then pushed brake pedal, indicator came on dim.. found it was the multiplug badly corroded. cut it out & fitted new 1. no problems since. fingers crossed regards, steve

 

[SB1500]

Can't resist but say 'Told you so!' :nerner:



Mine has been fine for a couple of years now.

The first time I investigated it I used contact spray and didn’t try scraping it off. That’s why it didn’t work then!

You knew the issue from the get go, thanks so much! Saved a lot of time and troubleshooting because of your early on help!

 

[DaveMcT]

Check all of your wiring connectors and earth points at the back of the car. Clean the copper/brass as necessary and use a silicone protection. Dont bother with WD40 as it soon evaporates so has no long term benefit. ACF-50 is good stuff. You can get it in bottles, aerosol spray and there's even a grease.

 

[koalar]

Update: I got it fixed. Turns out, it IS related to the back light - as you’ve all said all along.

Upon closer inspection, there was black oxide. Scraped it out with a screwdriver, on the plug and connector. Didn’t seem like I was doing much, but it worked.

- no more indicator lighting up steady when brake is pushed
- no more rear wiper initiating when front wipers are set to an on mode and the brake is pressed
- no more fast blinking instrument cluster indicator blinkers


Question for me now is... will this last? Or will it be an every so often job?

Glad to see it fixed. Well done

 

[Theleman]

Saw an interesting earth problem and how it affected the car.

[ame]https://youtu.be/gVvIsGJJaw4[/ame]