tach jumping

[BEAU2EVE@aol.com]

   I recently installed a pertronicx unit in my 1966 BJ8, and since that time 
my tach is not accurate. It works at a idle but when I rev it up it drops to 
nothing , Most of the time I'm driving I have no tach, when the rev's drop 
below 12 to15 hundread it some what comes back to life. Any thoughts on this? 
I'm 
quit sure the tach was good before, you know CRS.   



                Beau in R.I.