The Retrogauge Mini-Tach is easy to wire. There are three leads ... Route the signal lead through a rubber grommet located in the firewall, ideally where your Mustang's air conditioning compressor ...

Sealed both by an O-ring inside as well as a rubber wire seal on the outside ... 02.We found an unused vacuum port on the driver-side firewall, near the throttle cable, and opened it up to ...