Headlight not working - Please help

[Rymkykut]

Hi All,

I have noticed on my 2006 Megane estate 1.5 dCi that the driver side dimmed headlights are not working. I have bought 3 H7 replacement bulbs 1 standard and 2 xenon ones. I have tried all of them, but still no joy. I have tried these on the passenger side and all the bulbs have been working. Any ideas what should I check to find out the cause of the problem as I am clueless at the moment? Thought it might be the fuses, but it doesn't make sense as the dimmed lights are working on the passenger side.


Please help!!

[stephen1990]

Checked the looms?

[morganjake1544]

Unlikely you may think, but there are indeed separate fuses for left and right dipped beam.

Follow this link to page 48 and look for fuses 8C and 8D.

Hope this helps.

http://ray-lee.co.uk/megane/dialogys/MR364MEGANE8.pdf



I suppose it does make sense as one blown fuse still means you've got some lights. The chance of both fuses blowing and leaving you totally in the dark is quite remote.

[Rymkykut]

Thanks for the help guys. I am going check the fuses ans soon as I can, hope this is causing the problem. Will let you know.

[Rymkykut]

Today I have managed to open up the fuse box and checked all the fuses, but all seemed to be ok. There are many empty slots, without any fuses, all I can think of is maybe the fuse is missing. Could someone please help me to point out where the fuse for the right dimmed headlights should be?

Thanks for the help guys. I am going check the fuses ans soon as I can, hope this is causing the problem. Will let you know.

[davelowe]

Pull the connector from the bulb and measure the voltage when the lights are on the 'on' position. If you get 0V, the bulbs are not to blame. Ground the meter where the bulb holder sits so as to determine that the seat is not isolated from the chassis.

From then on, it's a process of following the diagram back from the bulb, checking every stage.

[morganjake1544]

Follow the link to P.47 (from my first post) and there's a diagram showing where the fuses are located within the box. The ones you need are in the top left corner.

[Rymkykut]

Thanks all for the help,

Will try to check the connections with the voltage meter as soon as can.

The location of the fuses in my fuse box is different to the ones on p.47 in the manual.....

[Rymkykut]

Hi all,

I have managed to check the dimmed headlight connection today with the multimeter. The result, on the side where the lights are not working it shows 6.5 V, while on the working side, for the same bulb it shows 12.5 V. Basically there is not enough voltage on one side to light the bulbs up. I just don't know what the next step is. Could someone please help.

Many Thanks,

[davelowe]

Set your meter to measure amps (ideally a fused 10A setting). Leave the bulb and loom dangling so that you can get access to it, then short the ground side of the holder to a good earthing point (negative battery terminal is a perfect source) with the meter. It should read 55/12 or about 4.5A and the bulb should light.

MAKE SURE that you are shorting the NEGATIVE side! Otherwise there will be sparks and bad things may happen.

This is to check the earth to the bulb is sound. If this doesn't work, I'm out of ideas (for the time being)!

You could do the same trick, but in reverse. Short the positive terminal to the battery positive, and the bulb should light.

At the end of the day, one or other of the terminals isn't supplying what it ought to (unless you put in a 24V bulb - this has been known to happen).

Let us know how you get on.

[MicKPM]

Hi all,

I have managed to check the dimmed headlight connection today with the multimeter. The result, on the side where the lights are not working it shows 6.5 V, while on the working side, for the same bulb it shows 12.5 V. Basically there is not enough voltage on one side to light the bulbs up. I just don't know what the next step is. Could someone please help.

Many Thanks,

It sounds like either a problem with corrosion somewhere on either a multiplug or at the fused link, a UPC fault or a wiring issue.

As above, start by looking for signs of corrosion at the plugs and possibly swap the UPC fuse for a new one. Then, if all else is good, start tracing the wiring loom back from the light to the UPC (the white multiplug at the very top and the black x16 pin connector from the UPC is the lighting loom).

Mick

[Rymkykut]

My dimmed headlights are working again!!!!

Today,with the help of my brother, we have identified (don't ask me how, he has the knowledge) which wire from the five could be bad/broken - it was the green one. Then, checked all green wires just before they are connected to a connector on the fuse box by cutting a little hole on the insulating pipe they run in, and then touching them with one end of the multimeter and touching the positive or negative side of the battery with the other one. As the all the green wires were fine I took off the black insulating tape from the bunch of wires running along the front bumper from the fuse box to the driver side headlights and voala I found a green wire which was broken in two places. Cleaned the wires, connected them and hurray the lights are working again

All I have to sort now out is my air con - but I have started a thread on it already.

[Rymkykut]

I almost forgot....... Thank you guys for all your help. It is great to have a place to discuss the issues with have on our cars.

[davelowe]

That's why we love em!