Just did an LQ9 and trans swap in a 2005 Sierra. After startup I noticed I didn't have a tach. Is it possible that the stepper motor went out? Before I parked the truck in November, my tach worked but my speedo didn't. It seemed to have swapped after start up. The speedo worked only slightly as my rear was on jack stands and I was running through the gears to fill up the trans. Where does the computer get the tach signal from?

 

Crank sensor by the starter.

 

^^^ x's 2