by Ed Esslinger, in the May 1997 RootesReview
If you are changing your Series IV Alpine to negative ground to use an alternator, ignitor, radio or other polarity sensitive device…Remove your tach first. While it’s well known how to change to negative ground, it’s easy to overlook polarity sensitive devices. Before re-installing the tach, the polarity must be changed to negative ground, Also, the pick up loop must be wound in the opposite direction than original. The information on how to do this can be found elsewhere in the Sunbeam Survivor.