[DeTomaso] Tach wiring help needed

[Larry Finch]

I'm helping a new Fresno owner install his 8920 tach adapter for his  
MSD ignition.

He called tonight with a question I can't answer.

He says (hard to see clearly, though) it appears two wires attach to  
the same stud on the rear of the tach: a light blue and a blue with  
black stripe.

Light blue is power from fuse 12. BL/BK should be tach signal.  So do  
these in fact land on the same terminal?

Doesn't seem right.

Anyone have a good photo of the BACK of a tach showing all terminals  
and wiring?

Thanks,

Larry