When I worked at the local GM dealer, a kid had taken his Dad's car out while Dad was out of town. I can't remember what model GM it was, but regardless--he'd disassembled the dash and snipped one of the wires to the odometer motor and driven the car all weekend like that. It was Monday and he was in panic mode because after doing a very-nice job soldering/heat-shrinking the wire back together, the odo didn't work. "JUST FIX IT!!" We couldn't, and the cluster would have to be sent out to a specialty contractor and the PCM may have needed repair as well. On a GM, if you cut that wire, the odometer will never work again once reconnected. I told him to go home and take his beating when Dad arrived, and next time around just unplug the damned speed sensor! Sure, you won't have a speedometer (which I consider generally unnecessary in the first place) and you'll get a "Check Engine" light, but at least everything will work when you reconnect it! I think it was Sybesma's Electronics that ended up fixing it, but it's been so long I can't be sure... but when Dad brought the car back to get it fixed, I remember the guy on the other end of the phone laughing... "Why didn't he just unplug the speed sensor?!"
