Headlight & Fuse box (engine bay) query

[JCarthy]

Hi all, just have a quick question if anyone can help. I had an issue where the battery was being drained due to the Headlights not turning off.

I replaced the indicator stalk assembly with a new item today but the problem was still there.

After driving the car and turning off the ignition the lights went off but after a minute or so they came back on by themselves and I noticed a "buzzing" noise from the fuse box area on the right of the battery.
After opening it up I pulled the relay for the lights and replaced with the one for the rear heated screen and it hopefulky seems to have solved the issue. Anyone had similar issues?

Looking at the Fuse box there was one wire running across which was disconnected.
Does anyone know what this is for. I connected it back up but it doesn't seem to do anything.

It's the white wire in the attached pic (taken from Google)
Any help would be appreciated.

 

[turkie172]

I investigated a car issue where the driver's dipped beam kept turning on and draining the battery overnight. Using a multimeter, you can disconnect the live terminal, set the multimeter to DC amp mode, and place it between the battery positive and the positive terminal connection to check for power drain. From there, you can pull connectors and fuses to identify the circuit drawing the most power. In my case, I had to replace the fuse box because the transistors inside, which control the lights, had failed. Disassembling the box is tricky and could cause more damage, but repair services are available online for around £85. Used units cost between £100 and £130, while new ones are rare and priced around £350. If the used unit is from a different model or engine, it will need programming to instruct the alternator how to charge the battery and will retain the donor car's VIN. Cars like the Modus and Clio Mk3 have the same model box until the facelift model but also require reprogramming but might be cheaper to source used.