Check my posting a few items down from your original posting. I had similar problems with my speedo coming on and off erratically. I'll be you are having trouble with your ABS check light too. The rear differential has a sensor just like those used at the front hubs for the ABS. In the rear, this sensor also signals speed to your speedometer. If the wires are broken, like mine, you will have speedo problems AND ABS problems. Also, pull out the sensor and remove all the metal particles stuck to the sensor. You may find this cures your problem. BTW: if your wire(s) are broken at or near the sensor, just solder them back and cover with silicone sealer, then secure the wires closer to the differential with a wire tie. Hope this helps....