:crazy: Tach gone crazy on me this morning. Fired up the car and ran it down the freeway about my normal 85-90 Mph and the tach was reading (5000) higher than normal. It was about 1000 rpm off from what it should be. All of a sudden it would jump back to normal and then do it again several times randomly. I am aware that I should check grounds and fuses for loose connections, but what else? Is there any type of common problem that causes this otherwise? This is the first time it's done it, so I'm curious where else to start. Any suggestions are welcome. Thanks!