Shift Light not working

Having an issue with my shift light. Not sure that it ever worked but heres the story. Ive got a MSD 44, Six shooter , 8168 controler. I originaly had the programmable autometer with the little digital tach in the middle. I never could get shift light to work so I bought a MSD little programmable one. It wont work either. Started with them going through a tach convertor then switched it to the tach output on the 8168. Still nothing. the digital tach works good but shift light wont activate. Any ideas? Kevin

 

Have you checked the output of the shift light controller? I had the same problem and found out the controller was switching to ground, so 12v was required at the light.