Hi, I'm changing over to CNG and need a tach wire. Does anyone have a wiring diagram to show which color wire comes out of the ECM to the existing tach or how to get to it easily? Or know of another way to get a tach wire? Thanks...

 

I would put this post in the classified part of the forums as that will be your best bet in finding what you are looking for.

 

I think he means to locate one in the wiring harness so he read the engine speed.
I dont know if ours has a conventional tach wire, our ecm works using digital canbus signals. I think there is a half tach signal white wire in the black ecm harness, but you need an adapter to get an analog tach signal if thats what you need for your system. Some have a 2cylinder setting. MSD makes an adapter too.

 

Try looking at an after market Cruise Control website for their directions. Check your PM, this might help.