I found the following thread most helpful. I have a 95 and couldn't see my warning lights when the top was down. Most frustrating to me was I couldn't see the parking brake light! I took SouthernGypsy's advice in this thread and ordered the bulbs he recommended and replaced them myself. It wasn't very hard. Now my warning lights are bright and I can see if my parking brake light is on even when my top is down and it's a sunny day!

Here's the link to the thread:
https://www.jaguarforums.com/forum/x...-124049/page8/

 

I used t-10 white led bulbs for the five instrument lights excellent results



























i used t-10 white led bulbs for the five instrument lights excellent results

 

...but being XJS dim, you can barely see them anyway...

 

Idiot lights on all the time?
Pull the two feed plugs in back one at a time. When the lights go out ckeck to see which lead on the plug is carrying 12vts. Troubleshoot from there

 

I found this interesting video on a XJS dash light improvement.