....and reading the factory service manual can be amusing, unless you are trying to figure out why something is broken. The running changes can be daunting to keep up with. As a aside, I once had the battery go dead repeatedly in the XJS. Checking the draw reavealed a less than 100ma draw. The battery continued to go dead. I kept scatching my head until I got home one night and saw a light fladhing on and off in the garage. Thinking, wtf, I opened the door to find the headlights bliking on and off by themselves. The culprit was a defectice headlight relay that had a mind of it's own and was turning the headlights on and off, and it wasn't made by Lucas. It was made by Bosch, in Germany.

I will give credit to Jaguar for having self-diagnostics with trouble codes readable without a scanner back in 1992.