I posted to an older thread about my headlights a week or so ago and apologise for that.
I realise now I should start a new thread.

I am trying to understand my headlights issue. The car is 1992 coupe, Canadian spec so with daytime running lights.
The headlights all work as expected except when the lights are on (the night/darkness switch position - position 3 - so nearest the steering column).
All lights are fine except the right hand headlight does not come on in dipped position. It does come on when full beams are turned on.
In the other two switch positions (positions 1 and 2), all lights work as expected - and the headlights come on as "Daytime Running Lights".
I see that the car has different fuses for headlights on at night and daytime lights. So I am assuming the following:
As the headlights come on as daytime running lights and as full beams in the night switch position - there is nothing wrong with the bulbs for high and low beams.
I have checked the fuses and they seem to all be fine. So there is no fuse issue.
Are the daytime running lights and the dipped headlights completely different wiring, even though the headlights look the same brightness - and are there different relays for them?
Does this mean the most likely problem is either the specific relay relating dipped headlights at night and do the right and left dipped lights go through different relays, or the wiring is the issue (bad wire somewhere)?

I was also curious as to why the fuse amps is different for the dipped and daytime headlights.

Bill
1992 Jaguar XJS Facelift coupe

 

Bill, I also have a Canadian 1992 coupe but can’t get at it at the moment to look, but don’t your headlamp units have a little 5W bulb in addition to the usual high/low one (which I think you’re referring to as dipped/full)? I think the 5W bulb is the daytime running light you are seeing with the lights off, and that your main bulb’s low beam is burned out.

This diagram shows the two bulbs as # 3 and 8: https://parts.jaguarlandroverclassic.../brand/jaguar/

You’d have to replace #8 (shop for part number JLM10587).

 

Bill,

As Greg has suggested, it just sounds as if the dipped beam filament of your headlight bulb has burnt out. Just take the bulb out and it will be easy to look at ait and check. Or just swap the bulb from the left to the right and if the problem now moves to the other headlight, that confirms it.

Cheers

Paul

 

Thanks. That explains something else perhaps - I thought the headlights, when daytime running lights, looked really dim!
And I thought low beams (dipped) should be brighter than that!
I will try that.
Thanks!

 

Bill,

Another thing: Canadian lights may be different to UK ones. But on UK cars, the first light position is what we call sidelights. But that position uses 2 bulbs. When the ignition is off, it just uses the small separate 5w bulb. But when the ignition is on, it ALSO uses a sidelight circuit in the main bulb. Maybe Canadian cars work the same?

Cheers

Paul

 

Paul, the Canadian (probably all North-American) X300s do use the 5W and the dipped main bulb when the ignition is on, but over here the 1992 XJS (AJ6 engine) shows only the 5W bulb when sidelights and ignition are on (the first switch position).

What’s you VIN, Bill? I have 180034 in Signal Red.