Supply to bootlid

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Kieron g
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Supply to bootlid

Post by Kieron g »

Hi. Trying to find out why nothing electrical on my hatchback boot lid works.
Thought might be an earth problem so tried taking numberplate light wires to earth via multimeter still nothing.
I appreciate that wires on hatch back cars can fracture where they flex at the opening,
It just seems too much that all the wires to number plate lights, rear wiper and central locking would all be affected also I notice that wires run down both sides of the boot lid from the roof.
Any suggestions / guidance on this would be appreciated.
I initially thought that the wires had been cut but this is a small hole in the top of tailgate opening which previously had been filled to stop water getting in.
Thanks
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Jaba
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Re: Supply to bootlid

Post by Jaba »

Sounds like a common earth point has failed. But I have no idea where this is from memory. Have a look at the wiring diagram in Haynes to see if there is one.
It would be sensible to check for 12v at the failing lights, perhaps you have already as I see you have tried earthing the numberplate already.
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Kieron g
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x 4

Re: Supply to bootlid

Post by Kieron g »

Thanks, yes had a look at wiring diagram in the hope that there was a common fuse.
Maybe is an earth, I used the boot catch as temporary earth for testing number plate light supply, I'll check this does work.
I was wondering where common earth might be, hopefully not in roof space as I already dropped headlining once for sunroof water leak
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Re: Supply to bootlid

Post by panky »

Try running an earth to the metal bodywork just to see if the original connection has broken.
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Dave_16v
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Re: Supply to bootlid

Post by Dave_16v »

From memory, a lot of earthing takes place under the n/s rear light. Can't remember if it goes up into the tailgate but there is a bolt behind that light with earth wiring connected.
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Kieron g
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1988 Citroen BX 1.6 RS (sun seeker)
x 4

Re: Supply to bootlid

Post by Kieron g »

Thanks, I'll try both suggestions making sure I have a proven temporary earth for the first. At least it comes down to basic principles on these cars. Praise the Lord
Kieron g
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2000 Citroën berlingo multispace 1.8i
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x 4

Re: Supply to bootlid

Post by Kieron g »

Ok. So far I checked live supplies at the boot lid and although I can't find any also cleaned the earth point connections Dave referenced behind the n/s/r light cluster.
My thought now is that there might be a multi plug somewhere which supplies everything to the boot lid which is defective , the only place I can think where all the supplies will be in the same area is around the fuse board.
I think I'll make it my next job on the car to remove what I can in that area to see where the wires go.
After that I guess I'll have to drop the headlining again (previously for sunroof drains) and check the wiring there.
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Jaba
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Re: Supply to bootlid

Post by Jaba »

The cables for the lighting don't come via the roof. They are flat cables at rear seat and boot floor level.
Still not clear if you have measured 12v anywhere at the rear end.
The Joy of BX with just one Citroën BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.
Kieron g
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Posts: 22
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2000 Citroën berlingo multispace 1.8i
1988 Citroen BX 1.6 RS (sun seeker)
x 4

Re: Supply to bootlid

Post by Kieron g »

Thanks for clarifying cable route.
I have seen the flat wires on floor and in boot when drying rain water but assumed these were for the rear lights which although removed now work ok.
The wires to the boot lid must then be routed up the c post on the drivers side and into the roof space.
There are no live supplies to any services in the tailgate, I removed the trim and checked with a good temporary earth.
Kieron g
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Posts: 22
Joined: Sat Nov 25, 2023 6:26 pm
Location: Goole East Yorkshire
My Cars: 2001 Citroën berlingo multispace 1.9d
2000 Citroën berlingo multispace 1.8i
1988 Citroen BX 1.6 RS (sun seeker)
x 4

Re: Supply to bootlid

Post by Kieron g »

Finally got to the bottom of this and solution was really simple.
As Jaba says the wires run flat along floor to back of car, they run all the way to the drivers side tail light.
On this car the flat loom goes outside the metalwork behind the light and then back in.
Just here as the loom goes back in there is a white multiplug which was the cause of my problem.
Even with this properly connected though without the rear light plugged in on the passenger side there was no earth as there is a small white plug where the main earth for the back end goes into that light and back out to the earth point.
The white plug with yellow wires can be seen on picture Dave posted.
Thanks for your help with this.