Drivers Side Headlight Not Working

Hi folks,

I have just discovered my dipped (main beam) headlight is not working on my drivers side. Fault finding I have already done is - change fuse, change bulb, plugged passenger side headlamp (which works fine on passenger side plug) into drivers side plug and still doesn't work. Only the side light works.

Could it be the headlight relay? The wiring loom in engine bay looks fine so would be surprised if that was the issue. Really hoping it's not the loom.

Any advice/help much appreciated as always.

Cheers,

Paul

 

Hello, Paul,

Many mk.3's don't have any relays in the headlight circuit as original equipment. Those that do have both dipped beams supplied by a '53' relay in a socket added on top of the fuse box. As you've tried a working light at the drivers' side connector, it does seem that the dipped-beam feed on that side is absent. I don't recall which side has black trace colours on the headlamp wires, but the dipped beam wires are Yellow and Yellow-black, while the main beam ones are White and White/black.

I take it the main beam works alright, if so then the earth side of the r/h circuit is okay.

I'd suggest using a test lamp to follow the drivers' side dipped beam wire back towards the fuse box, to work out where the circuit's broken

The entire front panel has its own small wiring loom, for the lights and horns. Check the large round connector for this, near the top r/h corner of the radiator. It twists to separate the two halves.

The two dipped beam feeds are routed to the front panel connector from the plugs in the rear of the fuse box. The paynes diagrams or preferably rubjonny's pdf's will show which particular socket and pin numbers.

 

Does the high beam work? If you have a multimeter check the live and earth? Next thing I’d do is slide the spade connectors out from inside the plastic block. They have a little tab on the spade which when released will allow them to pull out. You have to push them in then use a jewellers screw driver to release the tab then pull them out. Have a good look at them and make sure the wire crimped to the spade hasn’t corroded away. Give them a good clean up. Might be that simple.

 

Many thanks for the advice folks. I'm off to work now so will have a look at my car tomorrow. Hoping its nothing too serious. Rang an auto electrician before and they said £50 booking fee and £60 an hour labour!! haha.

 

I didn’t check the high beam so I will try that tomorrow. Might order multi meter off Amazon. Only £11. Not sure how to use it though so have to do some research.

cheers.

 

As a quick guide to using a meter;

Plug the Black lead into 'Com' terminal, and the Red into 'Volt-Amp-Ohm' terminal (the normal convention).
Select a dc voltage range which covers 12v.
Place the black lead on battery negative, and the red on battery positive. The reading shows the battery voltage, which is the most you can expect when probing the headlamp feed wire(s).
Leaving the black lead on -ve, touch the red lead to the dipped beam lead in the headlamp connector. If the lamp should be lit, a reading close to battery voltage should show.

I suspect there'll be no reading, but should there be '12v' present, the earth side is bad; the black lead is by-passing it, for the meter.

If there's no reading, open the front panel connector and check the dipped beam feeds on the 'car' side of it. If they're okay there, the front panel harness is damaged.

If the r/h dipped beam isn't reaching the front panel connector, find which connector and pin it leaves the fuse box from*, and check for it there. If it's present there, then I'm afraid the wire may have broken in the engine compartment harness. The black lead can be moved to a good earth point nearer the fusebox, such as the brown plastic multi-terminal socket on the 'A' pillar.


* Paynes says the r/h lamp, from Fuse 2, exits at connector 'A2', pin 3. The l/h lamp uses A1, pin 1.

 

There are loads of videos on YouTube showing how to use an auto multi meter.

 

Hi folks, thanks again for the replies and advice. I’m working on the car right now. This is what I’ve discovered…

the yellow and black and brown/black wires were down by the alternator belt and they were sheered. I have no idea where I am supposed to connect them. There are no other loose wires that I can see. They are attached to the loom above the radiator.

The brown and blue wires are a repair I did for the fog light.

Pretty sure this is the root cause of the problem.

anyone know where I need to connect these two wires?

thanks In advance.

Paul

 

Both the yellow/black and brown/black are showing 12v on meter when ignition on and light switch on.

 

Also, the main beam works fine.

 

Sorry mate, if it’s a mk3 it’s a bit out of my area experience. Those wires could be for headlight levelling motors. On the Mk2 left and right side wiring are the same colour. Have a look at your good side, that’s working ok, and see how that compares with your failed side.

 

Thanks Jonny, I’ve secured the horn wires now and put them out the way. The wire in drivers side headlight is yellow. Passenger side is yellow black.

Can’t see any damage at all unfortunately. Might have to leave car with auto electrician in the hope they can solve mystery.

thanks to everyone for your help and advice.

Paul

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