I've had an odd problem pop up intermittently with my '98 Esprit. When I start the car, the yellow ABS light will stay illuminated (solid, not blinking), and the speedometer will not work. (The tach still works.) After driving for about 5 to 10 minutes, the light goes off and the speedo starts working. I had it in with a good mechanic earlier this week, and he didn't find anything, and no codes were triggered in the computer. Any ideas what might cause this? It's happened 3 or 4 times recently. Thanks!