Can anyone help with this , the rear number plate lights are intermittent it is not the bulbs does anyone know where I can obtain the complete circuit board with the electronics from?
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Technical Rear Number Plate Lights
- Thread starter sammy19
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Technical Rear Number Plate Lights
Hello,
As far as I know, the most problematic part of the rear door installation is the part between the body and the door - the cables tend to brake inside the rubber hose that should protect them
There are several threads on that on the forum.
Have you checked it?
As far as I know, the most problematic part of the rear door installation is the part between the body and the door - the cables tend to brake inside the rubber hose that should protect them
There are several threads on that on the forum.
Have you checked it?
OP
OP
Yes I have checked the threads , thanks I was just wondering what to buy everything or just the cijcuit board.
Don't buy anything before you find the fault
Here's the eLearn doc for the 2007+ car. I can't remember when they changed it (2009? 2012?) and have no idea from which year your car is.
Here's the eLearn doc for the 2007+ car. I can't remember when they changed it (2009? 2012?) and have no idea from which year your car is.
Derbyfella
Established member
Had an intermittent issue with wife’s (66 plate) rear lhs number plate light going off. I’d take the cover off remove, inspect replace the same bulb and the light would come back on with no warning,
Until last time where the bulb was smoky black, I replaced and no warning light since.
Until last time where the bulb was smoky black, I replaced and no warning light since.
This really sounds like the rear hatch wiring issue?
Best adviceDon't buy anything before you find the fault
OP
OP
Yes I have had all those done and the boot covering the wires changed, the electrician you did this for me says it is the circuit board is the problem.
Thanks for the diagram, I took the car to an auto electrician, it was the same one I had repair the wiring harnes a few months ago and he recheched the wiing and he said there were no more wires that were broken but in his opinion the fault is in the unit itself,but he said whatever he did the lights are working again but he has no explanation why.Don't buy anything before you find the fault
Here's the eLearn doc for the 2007+ car. I can't remember when they changed it (2009? 2012?) and have no idea from which year your car is.
OP
OP
I know it does John but I have had it all repaired and a new boot fitted and it did work when I got it back, I have only used it a couple of times since it was done as I have had an hip replacement but when I used it last weekthe warnig lights were lit number plate fault. the electrician can not explain why, he is know to me and I do trust him. I have to say I do agree wih you that it is most likely to be a wiring fault but he assures me it is not.
The wiring diagram shows that the numberplate is at the end of the line, with relatively few problem areas. I don't see much possibility of a circuit board problem.
1) Wire into rear hatch
2) Rear hatch
3) Wire out of rear hatch
4) Connectors from the wiring to the bulb/led
1) Wire into rear hatch
2) Rear hatch
3) Wire out of rear hatch
4) Connectors from the wiring to the bulb/led
Looking at the doc I'd say that if it would be an earth issue at the earth point, rear light clusters would also have problems (italics are pasted from the eLearn doc):
Rear light clusters F030 and F031 and no. plate light unit F055 are connected to left-hand rear earth C030.
If it would be a problem on the positive feed from the BCM, the boot opening switch would also have problems:
Body Computer M001 controls the activation of the side lights; in particular:
from pin 15 of connector F, for left and right-hand number plate lights built into no. plate light and boot opening external
switch unit F055 (pin 1).
However I'd check both for continuity. And when the problem reappears, try to identify if one of those is also failing.
Rear light clusters F030 and F031 and no. plate light unit F055 are connected to left-hand rear earth C030.
If it would be a problem on the positive feed from the BCM, the boot opening switch would also have problems:
Body Computer M001 controls the activation of the side lights; in particular:
from pin 15 of connector F, for left and right-hand number plate lights built into no. plate light and boot opening external
switch unit F055 (pin 1).
However I'd check both for continuity. And when the problem reappears, try to identify if one of those is also failing.
OP
OP
Yes I know what you say but there are a few cases on this site showing wateringress in the main unit witch if you look at the pictures on this site show a considerable amout of corrosin on the soldered wires on the circuit board, the auto electrician is a family friend and he does have his own buisness and I do trust his word.
Do you mean the body computer?
OP
OP
I purchased the complete repair loom and boot for this repair and that was used the rear intreior panel was remover and the repair piece grafted in , all the
wires grafted in , the thick wires for the windscreen heater and the water tube for the windsceen washer all of it, it was not just a replace the broken wires so I am at a loss to decide what to do , the auto elec is adament it is water ingress on the circuit board but as I said it is working now so stumped at the moment.
OP
OP
No when the rear number plare light fitting is opened up the wires terminate on a circuit board.and it is this board can suffer water ingress and corrosion
I get it now
There's this board that serves both the lights and the switch. I remember a photo in another thread here, might be from the 500, too.And yes, if there's corrosion there it might affect how it works. I don't know how it looks in real life. I had a similar problem with my non-FIAT daily. Water was getting inside the numberplate lights housing. I've read that it's a common problem and so the bulbs will be failing on a regular basis. Trying to replace the bulb on one of the first cold mornings I had the car I broke the plastic hook that was holding the housing in place. So I decided to buy LED lights instead. They were ment to be sealed for life, after like 4 years I had to remove the sealant, clean the PCB, resolder the connections and finally I used a professional sealant as I don't need to replace the LEDs anymore
And this time it will probably be for life
I understand now. The confusion has arisen because you've been asking for a circuit board when you've been needing a new light fitting. It's not possible to buy the circuit board on its own.
If you search "fiat 500 number plate light" you can find them easily.
