thank you, I hate replying on my phone cuz and make replies super short because of. i am not just hooking up a new link with my fingers crossed...I have the service manual and diagram for the car. I am suspecting the Tach I hooked up has a short in it, as when I first fired up the car with the new dash harness in place it was fine, this happened after hooking in the old tach which my son(this is now my sons car I am still working on it for him though) said would stop working in n the past intermittently.

I will use your suggestion for trouble shooting with a light bulb etc to find the problem so I don't burn up more links, thx!