i recently installed a new speedometer unit in my 96 v6 accord due to speedometer and odometer issues. after i replaced it they both worked fine but the tach is acting wierd. it still idles about the same but when you get on it the tach moves way too fast . it redlines at around 6 but now goes well into the red like around 8 or 8500. does anyone know why? could it be the speedometer cluster came out of a 4 cyl instead of a 6. thanks for all your help

 

Ya you got the wrong cluster. The tach is based on on and off signals from the coil. On the 4 cylinder you have less on and offs on the v6 you have more on and offs. You may be able to just swap the tach from your old cluster be gentle.