Lights and wipers started on their own

I was getting faults coming up on the screen saying faulty fog light, faulty side lights, main beam fault then it said rear light faulty, I happened to notice the driver side rear cluster was a replacement from scrapyard as it had the code on it with a marker pen. I removed it and put another one on from the scrap yard and all the faults stopped. I also noticed as I took both rear clusters off that only one was earthed to the car from cluster to the bolt on the car. Is it normal for there only to be one side being earthed to car. And that’s all I know

You can't see the earths of the rear clusters to the car on a standard, unmodified C3.

I guess yours has been changed to include the rear cluster mod?

If so, has it been done correctly and with enough safety in mind to avoid damaging the delicate electronics of the car.

You will have to do some investigating.

But I can say that the each of the left and right side cluster plugs and cables look exactly the same as each other on a standard, from the factory car.

ssybrg10 wrote: ↑Fri Nov 25, 2022 1:02 pm . I removed it and put another one on from the scrap yard and all the faults stopped.

This was probably due to disconnecting and reconnecting the plug. Rather than a faulty cluster.
I'm going to say (without actually looking at the car) that my guess is there is nothing wrong with the cluster you removed and replaced. It will be down to the high resistance on the actual plug of the car. Just reconnecting it can be enough to wipe the connection clean and make a good enough contact.



But whatever causes the original problem is still present.

Hello and good day to you, so I was waiting for my new second hand fuse box (BSM) to arrive and was looking at the old one which was still on the car. I had to connect the battery again in order to open the boot so I could remove the extra earth wire attached to one cluster of light at back of car. Before connecting the battery I removed the 25 amp fuse that said was for the starter motor. I had to use players as this was melted together with the box. The can only actually started with the fuse and key in my hand. I got a fright obviously do rushed to remove the connection to the battery again. Leaving the rear cluster until new fuse box (BSM) arrives.
It arrived at lunchtime on Sunday so I took out the old box and had a look at it. It was impossible to open as tge heat must’ve fused it all together and that could possibly explain the engine start after removing the fuse. Anyway all was good when I connected everything up again now to the new box. No lights or wipers going on and no start attempts. Looks solved. Only thing I need to do is find the issue of the water I believe come through the windscreen at the bottom as it is quite wobbly. I have a feeling it was not put back on properly when some repairs were made before I got the car. Oh and the BSM was a second hand one that was already on the car so this issue has happened before. Tgere was the yellow paint from scrapyard on the underside of it so I assume it already done this before. Thank you for all your assistance and I hope this post can help someone in the future.

On removing all scuttle panel and wipers I found that the drain hole on the drivers side was completely covered with old leaves and gunk. I would imagine that it filled up the space like a tub and overflowed right into the engine compartment. So now it is cleaned up and everything is working as it should. Thank you again