Installing a tach, what did i goof up?

[GotToGo]

Yeah, I don't have one of those.

Is there still a tach wire somewhere?

[geezer101]

Yeah, I don't have one of those.

Is there still a tach wire somewhere?

Yeah the '88 won't have it as it's pre FI. Those extra connections are for the ECU diagnostic and tune reset. You won't have to worry about a bad sensor or ECU The trace for it should still be in the main instrument socket plugged into the dash. Isolate it and life is easy. I know you're going to ask me what colour is it - I've McGoogled it and can only find schematic diagrams. Typical...