How to test a Camaro, Firebird, Corvette, or other early GM Tachometers for proper operation (Updated 2021)

GM Tachometers between the late 1960's and early 1990's had a common problem. They fail!

How do you know the problem is the Tachometer and not the distributor or the ignition module?

You can switch out parts and hope it fixes the problem, for now. Or, you can test the Tachometer.

Once you know the problem is the Tachometer, you can replace or repair the correct parts.

We sell replacement Tachometer Circuit Boards for 1969-92 Camaro.

We also have available a Tachometer Tester tool. Here is a short demo video of the testers in action. 

(update 2021 - This tool is now on the 3rd edition. The newer version functions the same as this older version in the video, but is more precise and has more usable settings.)

Some common Tachometer and Testing hook-up locations.