CDI System - Dizzy signal

[Gene Kunselman]

I have an 83 911 SC with no spark from the coil. Have read all the postings and threads but have not seen any discussion on the type of signal or how to check that a signal is being sent to the CD box from the dist. Way, way back, Loren said something about the signal being a negative 1. In recent discussion, Fred explained how to simulate the trigger signal to the CD box using a AA battery.

Taking these two replies, I assume the trigger signal from the dist (green wire) is a negative 1 volt or greater. Is this correct? If so, couldn't I measure the trigger signal by connecting my Fluke to the green wire pin and the green wire shield pin and turning the distributor with my cordless drill? When I did this the result was only a max of about 600 mv. Any help / explanation to get me on the right track is appreciated.