Have a problem that has been bugging me for a while. My wiper does not operate in Auto, and will only work for a minute then stop, randomly at different places. It won't stay on when in low or high, will work for about 15-20 wipes then stop. I replaced the relays, and judging by the fact that they "work", it shouldn't be the motor. Any ideas?

 

I had this EXACT problem in my 1998 XJ8 VdP (random stopping, intermittent; sometimes would not go to home position when switched off). Relays were fine - problem was within the motor and resolved with a new motor ($900 for Jag motor, but I purchased a generic Bosch motor for around $150). Has worked fine since installation around 9 months ago.

 

Balcanthez: Scottish Chap is correct. There on contacts on the motor unit that become dirty/corroded over time. The views on here are split. Some say you can open up and clean contacts to correct. Others opt to replace motor. I picked one up off e-bay cheap and replaced. Cured same issues I was having. It can be tricky removing old unit, but, doable. Search this site for how to's. Good luck.