Classic Instruments SN74Z Speed Signal Interface

Classic Instruments SN77 Electronic Transmission Signal Converter Box is used to convert signals from factory VSS (vehicle speed sensor) electronic signal generators and/or the computer(ECM) output to work with a "16-pulse" input (16,000 pulses-per-mile) speedometer.  The "16-pulse" speedometers from Classic Instruments typically will utilize 12 dip-switches on the back of the speedometer case.

Please refer to Classic Instrument's 11 Common Technical Questions for proper calibration and troubleshooting tips.