My friend has a 99 z and is having trouble hooking up his tach. i got info from the ls1 mods page but its for 98's only the link for the 99 and up was a dead link. i need to know exactly what wire to tap into for histach to work. he allready bought the autometer adapter and he said it sux that the tach is way off from the factory one. thanx fellas!

 

pin 10 on the red connector on the ECM. should be a white wire

although i tried hooking up my proform shiftlight to it and couldn't get anything to work. was having trouble with the whole "4 cyl mode" that you ahve to do with the ls1

 

We hooked up my Harlan to the white wire.