Okay I did HVAC, key ring and cluster. My wife was helping me with the cluster and the mph and tach came off! I was like wow I'll just mark where they were and put them back on no prob. Well I was wrong. the gas and temp are fine and accurate, but how do I calibreate the tach and speedo? the car off I can move them to zero, but when I turn on accessory the speedo goes to 20 and the tach's abot 2300. when running the tach idles at 3000 and the speedo is still 20 off. Do I need to go to the dealership and have them reset?