XJ6 Series III Headlight Conversion/ Updated Lighting

Has anyone updated to LED lighting for front XJ6 S3 headlights or other lights (front/back, side marker, interior etc)? I have european lights with 7" (H4) outboards and 5 3/4" (H1) inboards. Lighting is so dim at night and looking for direction for replacements/ updates/ recs
Thanks for any ideas or help.

There are regular posts on Jag-Lovers about swapping out incandescent bulbs and installing LEDs. If you search the Jag-Lovers archives for “LED headlamps” you will likely find a bunch of posts. It seems to me that the results are mixed and that finding and installing the correct LEDs can be more complicated than expected.


I replaced the H7 bulbs in my 2003 MGTF with these;

They really improved the light output with a nice beam throw.
Obviously not suitable for the XJ headlights but I’m sure there are other LED’s out there.
Google H4 LEDs

I have hi/lo leds in the outer lights and work well - much brighter. My hi beam inners current have sealed beam aircraft landing lights which are very bright but I am soon to swap them out for Leds - will not be any brighter but the yellow colour will be gone and will match the LEDs in the outer housings.

Oh by the way, the outers are not European 7" housings - they are the world fitting size - except for the US.

Be aware that it may be the reflectors that are at fault, Donald - and bulbs alone may not be the best solution…? Nothing wrong with upgrading, of course - but there may also be issues with high resistance in your headlight circuits/voltage loss…

xj6 85 Sov Europe (UK/NZ)

That is what I did.
H4 and H1 Halogen, high beams in all four, plenty of light but they are powered via relays directly from the battery, made a huge difference.

If you don’t want to install relays LEDs is the only way.


before spending $$ for LED bulbs, take Aristides advice and check the reflectors first - if the lower third is golden brown you won’t get a lot more light.

Second, check the voltage that arrives at the bulbs - if there’s only 11.3 V left at the bulbs … no wönder the light is dim. Short from installing relays it might help to simply clean, file and lubricate all contacts (at the headlight, at the fuses, at the bullet connectors, at the ground).

To be sure: even a perfect H4/H1 setup will be worlds apart from a modern LED matrix light, but still, for decades H4/H1 was state of the art and made most every driver happy. At least I am …

Good luck


75 XJ6L 4.2 auto (UK spec)