I'm working on my LS swap and I have 1 last thing (other than tuning) to complete that I cannot figure out so I am reaching out to see if others have any advice or guidance. I am using the factory gauge cluster in my car (92 Firebird) and the tach is not functioning as it should. I've searched high and low on this forum and the interwebs for others who've encountered the same issue everyone and how they resolve it. Any guidance would be really appreciated.

• There is voltage from the tach wire.
• Using Dakota Digital SGI-100BT.
• Using v8 gauges, but also have a v6 gage to help test.
• Wired a resister (1k ohm 1/2 watt) to a fuse protected 12V + Key Source. Using the same 12V source as the Dakota Digital box.
  • Tried wiring this by itself (no Dakota Digital box)
  •  
    • and also tried wiring this before the Dakota Digital box.
  • HP Tuner Settings: 3/3 (High/Low)
  • When I use the Dakota Digital box and send a test output the tach moves. Below is the settings from the Dakota Digital app.
    

 

You have HP tuners with a GM engine ECM? There's an output pin from the ECM itself that will drive your tachometer.

 

Thanks for the quick reply! Yes, I'm using HP Tuners with GM engine ECM.

I'm currently using that wire, but unfortunately I'm experiencing issues and not able to get my tach to read properly. Hopefully I overlooked something easy and it's something easy to get the tach working.