I'm attempting to install a factory speedometer on an 2003 Trailblazer, everything was hooked up according to the directions however its not working. The needle seems to be pulsing off the coil power but not reading the sensor from the wheel. The battery for the quad was dead when I bought it could this be the problem? Any suggestions/help would be appreciated. Merry Christmas....

 

yes more than likely, adequate battery voltage is needed to run the speedo. I wouldn't suggest running it without a fully charged battery as you could fry the speedo because when power is generated the voltage in battery needs to be good otherwise it will apply too much voltage to headlights, taillights, speedo!!!