The only Tach tester that I know of that can test it outside the car, works great. A dial would be better than buttons.
See the Video tab above for a couple short videos showing this tester in use testing a speedometer and a tachometer.
You can never have too many good tools. Our popular tester is now on the 3rd edition (2021). This Digital Tester reproduces the signal type and frequency that replicates the signal that comes from the vehicle's tachometer and electronic speedometer signal sources.
Power Settings: ON/OFF. Frequency settings: 1Hz-1000Hz. Includes frequency to RPM table. Works with 1-12 cylinder engines. Duty cycle adjustable.
A must have tool for testing and repair of late 1960's and early 1990's tachometers and electronic speedometers.
Fast and simple set-up - takes @ 1 minutes to set up and begin testing.
This Digital Tester produces:
(1) 12 volts DC current to power the tachometer or speedometer.
(2) Low current DC frequency adjustable pulsed signal - This provides the RPM or speed signal to the tachometer or speedometer.
(3) Adjustable duty cycle.
Includes: (1) Digital Tester (2) 120 Volt AC Power Supply (3) Instructions
Product Note 1: This tester is compatible with tachometers that are driven by a circuit board. It is not compatible with tachometers that are simply a coil, such as early 1960's and earlier model year tachometers. It is also compatibly with many electronic speedometer's that use a pulsed signal to provide speed information to the speedometer.