Defender light issue.

Hi all i was wondering for some advice please. I currently have an 130 300tdi crewcab defender and been experiencing issues over the past couple of months regarding the lights / electrical system. I do apologise if this is not in the right section as this is the first time i have visited your site. The LED headlight starting flicking over time now has resulted in one side not working with it switching sides. High beam does not work and also switches of radio and interior light. The horn all of the sudden does not work and switches off the radio and interior light. LED indicators all come on at once when signaling. I have tried cleaning up the earths as it sounded like the best option to me as this is what i thought it was but this has made no difference. The main earths i could see is around the transfer box with one on the bulkhead. I am still trying to learn as i go along as the defender is in need of restoration new chassis / bulkhead and i am wanting to do this myself. After replacing all the bushes and doing some welding on the chassis over a month these problems shown themselves the LED headlight always played up slighty in one side being dim i switched the headlights to see if it was my led rather than the electrics but it was not my headlights. If anyone could give me some advice i would greatly appreciate it.
Many thanks.

Electrical issues in defenders are usually earths.

could be old wiring that’s chaffed through making the electricity take a different route.

Run a temporary earth directly from the battery -ve to the engine block and see if that improves things. A jump lead will suffice. If it does the. It’s deffo an earth issue.

Flickering can also point to a dying LED, i believe, have you checked it directly?

As per @flat , start with proving the earth/s. Then move onto clean 12v supply, then onto each light function.

Many thanks all for the advice. I have tried making a temporary earth this evening to see if this is the problem unfortunately has not made a difference. I have also prior to the headlight not working completely switched the left side with the right to determine if the LED was faulty or my electrics but it seems my electrics are at fault as it still flickered. As suggested i will have a good look to see if any wires have been chafed and to look at each light functions. My 130 is ex unity and has had hard life with electrics being bodged to run additional wires and i do apologise if silly question as i am unsure but can the wiring loom be bought in sections? Or a section which is more problematic than another for causing such a fault?. Many wires have been cut to add more for aftermarket immobiliser which since has been removed. Is there anything else i could check? Or any tips it would be greatly appreciated.
Many thanks for advice.

Yes you can, try auto sparks - they do looms and loom parts