My '99 XJ started weirding out on me today. Driving down the road at a steady 60mph, I suddenly saw the airbag light come on and the speedo went to zero. The tach also went dead as well. A few seconds later the gauges sprang back to life and the airbag light went out. Later it happened again, and I tested the cruise control switch while the gauges were still non-functional and it wouldn't turn on (no indicator light). A few seconds later the gauges came back online again and the cruise switch/indicator worked again. The small gauges (oil, amp, temp, fuel) aren't affected. What in tarnation is going on??? Do I have a bad ground somewhere? A failing clockspring? Speed sensor? If anyone can give me some good ideas before I start tearing the dash apart I'd appreciate it.