Headlight issue...

Post Wed Jan 18, 2017 4:36 pm

I am a bit stumped...

My left headlight is not working ...low beam is fine, high beam is fine...

I have checked Fuse 13
I have changed the main bulb
I have checked that it is clipped in correctly

What am I missing?

Thanks in advance for any help...

Post Wed Jan 18, 2017 6:30 pm

Gavla wrote:
What am I missing?

The common earthing arrangements.
Connect a piece of wire to a good body earth and touch the other end on the 'outer' of one of the bulbs to confirm.

Post Wed Jan 18, 2017 6:43 pm

Gavla wrote:I am a bit stumped...

My left headlight is not working ...low beam is fine, high beam is fine...

Sorry, what's not working?

Ben

Post Wed Jan 18, 2017 8:22 pm

BenHar wrote:
Gavla wrote:I am a bit stumped...

My left headlight is not working ...low beam is fine, high beam is fine...

Sorry, what's not working?

Ben

Yes, I know the initial statement makes no sense at all, but I'm assuming he means the matching lights on the other side are working.

Post Wed Jan 18, 2017 8:49 pm

You're probably right, Brian.

Ben

Post Fri Jan 20, 2017 7:43 pm

Sorry gents, realise my initial statement does not actually make sense...my bad...

The left high beam works fine
The left park works fine
The left dipped beam does not work

Thanks Brian

Post Fri Jan 20, 2017 9:40 pm

Check that there is power to the feed and that the earth is good, as Brian said.

Ben

Post Sat Jan 21, 2017 12:40 am

Check the plug between the headlamp unit and the loom

Post Sat Jan 21, 2017 7:19 am

Jiggle the wires from the plug and watch the light on the off chance the connection is partly broken (it is on mine) unsurprising after 25 years of vibration.

Post Sat Jan 21, 2017 10:52 am

As with any electrical fault that is likely to be a 'poor connection' or similar, the approach should be similar to that of disarming an unexploded bomb. Disturb nothing until you have to, and keep as far as possible away from the likely site of the fault until you are certain of exactly where the fault is. This avoids 'accidentally' 'curing' the fault without knowing what you've done, only for it to return sometime later, and/or introducing faults that you didn't have in the first place.
Before wriggling or tugging anything, the rear cover of the light should be removed, exposing the base of the bulb, the lights turned on, and firstly a wire should be connected from the outer base of the bulb to a good body earth, and secondly the wire should be tried from battery+ to the centre pin of the bulb.
One of these would be expected to make the bulb light, assuming it's not blown, and if the bulb lights when connected to battery+, note if the bulb on the other side of the car lights as well. If it does, you have confirmed that the path from the fusebox to both lights, and the fuses themselves are OK.

Post Fri Jan 27, 2017 5:05 pm

Ok...so I finally got round to checking the above...

I can confirm that the Dipped Beam works when I connect the outer base of the bulb to a good body earth.

I can also confirm that both Dipped Beams work when I connect batter + to centre pin of the bulb.

I can also confirm that it appears that I have developed a battery drain

could this all be connected somehow?

Post Fri Jan 27, 2017 6:39 pm

Gavla wrote:
I can confirm that the Dipped Beam works when I connect the outer base of the bulb to a good body earth.

I can also confirm that both Dipped Beams work when I connect batter + to centre pin of the bulb.

?? That shouldn't happen! Only one of the two tests should make the bulb light (unless you did the second with the earthed wire in the first still connected.)
If that is the case, then your fault is somewhere along the earth wire (brown) from the light to its earthing point on the LH inner wing.
Most likely to be near the headlamp end.

Post Fri Jan 27, 2017 6:44 pm

Mmmm... Not sure what I did wrong in that case...

Thanks Brian, I will check the earth wire in the morning.

Any suggestions for the the battery drain?

Post Sat Jan 28, 2017 10:30 pm

Gavla wrote:
Any suggestions for the the battery drain?

Connect a milliammeter in series between the battery negative pole and a good body earth, and go from there.
Around 30mA is a normal quiescent drain, but up to around 80mA is OK, if there's optional equipment fitted.
Open a window first, in case the central locking is activated by the battery being disconnected and reconnected.
A good technique is to loosen the battery clamp, push the probe of your meter vertically into the top centre of the battery pole, then lift the battery clamp off around it.
This avoids disconnecting the battery at any time, and any surges that may occur when you reconnect it that may blow the fuse in your meter.