Hello everyone. I'm new to the forum and couldn't find a post/thread that has the answer to my question. I'm looking to upgrade my xk8 fog light bulbs to led.


I know that the bulb size is H1 and that bulb fits into a base that connects to the wiring. The outfit that I'm trying to upgrade to offers a H1 size, but it wont fit because of the base that the bulb plugs into in the fog light. I would like to know what size that plug base is. Essentially, I have to order a light from them that already has the base connected to it, not just they bulb itself like a normal H1 bulb replacement.


The fitting and shape/size looks similar to the 9006 size light, but I don't know for sure. Again, It's the black plastic elbow shaped connector that the H1 bulb plugs into and then connects to the power source wiring. I've also "heard" that it might be interchangeable with the H11 size? Or is it not a standard size at all? I just need to know what size it is.


Any information would be helpful!


Many Thanks.

The H1 is a single filament bulb with a P14.5S base.

He's taking about the base that holds the bulb in the light housing. Looks like an adapter. The bulb plugs into the base, it has two twist tabs and then the harness plus into the adapter.

If you're trying to do hid's an h11 will work but you will have to trim one of the tabs a bit. If you are replacing it with a halogen bulb a regular h1 will work but you have to reuse the stock adapter.

Hope this helps.

George

Cattitude and Tommy, thank you both for replying. The information was very helpful.


Tommy, you're correct that base adapter is exactly what I am referring to. I'm not upgrading to HID, but a new cree led system. It's very similar to HID in the sense that it has the bulb, wiring harness and a power ballast instead of what would be the ignitor ballast for hid. They have the H1 size, which I already ordered and received, but didn't know that the H1 fog lights on an xk8 have that base adaptor.

So is the H11 size the closest fitting base to what the H1 bulb plugs into? I was hoping there was an exact match because the new bulb is mostly aluminum and I'm not sure how easy it would be to trim. It's one unit, bulb attached to base. I'm just wondering about the plug connector size and the three fins where you insert and twist to attach the lamp housing...


Below are pictures of the H1 bulb and adaptor.


Thanks again!

Sorry, George, You were correct, I typo'd Cattitudes name instead of yours! Apologies. But thank you both for your input.

I think it's one of the 3 'fins' that gets trimmed to make the H11 fit.

My 2006 XK8 manual says the Fog Light Bulb is an H3 not an H1. My right one is not working so I was thinking of replacing it but am reluctant to do so until I have a replacement bulb in hand (appears to be some work to get to it). Other posts I see references to H1 bulbs, so I am concerned about which is correct - H1 or H3.

And I am OK with whatever is correct (as long as I can tell) and don't need HID or LEDs with a lot of conversion work to fuss with. Long Life bulbs, perhaps.

H1 or H3, that is the question?
John

This is the Jaguar bulb chart:

That page is just like in my Owner's manual which says Front Fog Lamp (bulb) is an H3. But various lamp companies all say it is an H1. PIAA bulb chart say H3 first year (1997) and later are H1, so perhaps Jaguar changed and did not bother to change the manual (mine is 2006).
I think I will order H1s and hope they are correct.
Thanks,
John

https://www.jaguarforums.com/forum/a...-bulb-base.jpg

By the way I'm in the USA...