This is the strangest thing my 99 XJ has ever done. I was on the trail a while back and it started to rain. I turned on my windshield wipers and the fronts didn't do anything but the rear wiper started going. Then I turned the wipers off and the rear kept going for like 30 min. Later in the day I tried it again and the fronts worked fine. Its done it several times since then and i'm stumped. Any ideas? I didn't even think they were wired anywhere near eachother.