Found a wire
Once again I'm compelled to remind
SERVICE MANUAL
For 73, look up the connector diagrams in the rear of section 8 Engine bay connectors are "CE" and "instrument" panel connectors are "CI"
These diagrams start about page 8-164
If you can't find it post back. You MUST try first.
I'm gonna start charging for this, and it ain't gonna be cheap....................