Tach & rev limiter on same circuit?

[dart_68]

Quick question, hopefully. My ignition coil has a tach lead. I want to install a rev limiter that can use the tach signal. My question is can I connect both to the same tach lead and have both work properly?

Thanks.

 

[67Dart273]

Need more info about your actual ignition system. Some sort of CD/ MSD?

"Conventional" Kettering sometimes called "switched" ignition systems work similar to breaker points........the box.....like the old Mopar ECU or GM HEI ungrounds the coil NEG to make a spark. That coil NEG terminal is where you hook a tach. It also is where you hook grounding type rev limiters.........which monitor RPM, activate, and then start to short the coil NEG as the RPM triggers the limiter.

If you have some CD or other exotic/ aftermarket box, no way to know at this point

 

[dart_68]

Need more info about your actual ignition system. Some sort of CD/ MSD?

"Conventional" Kettering sometimes called "switched" ignition systems work similar to breaker points........the box.....like the old Mopar ECU or GM HEI ungrounds the coil NEG to make a spark. That coil NEG terminal is where you hook a tach. It also is where you hook grounding type rev limiters.........which monitor RPM, activate, and then start to short the coil NEG as the RPM triggers the limiter.

If you have some CD or other exotic/ aftermarket box, no way to know at this point

I have an HEI 8 pin module with correct coil being triggered by a standard Mopar distributor. It's the coil that has the tach lead that I am currently using for the tach. Wondering if I can add the limiter to the same tach lead.

 

[67Dart273]

The tach lead on an HEI is nothing more than the NEG side of the coil. If that is where the rev limiter says to connect in the destructions, then "that is where", so yes