So I was driving my 94 xjs on the highway and it just cut off. I pulled over and started it again and after a mile, it just shut off again. Any ideas what I should try and troubleshoot? Thanks

 

That happened to my 01 XKR only once so far its in the shop now and they tell me that
the Negative clamp on the battery was broken and that there are 2 relays that need to be replaced. Hopefully that solves the problem, its not save to loose all your power when
your cruising the the highway at 140k. Hope that helps?