Just connect My timing light now Tach wont work?
 

I was just timing my new motor and I hooked up my digital timing light. On my Timing light it has a wire that goes to the + side of the coil and then it gives the rpm readout. My tach was working fine befor I hooked up the timing light now it is dead? Anybody have any ideas what I broke. 1977 usa with 2.7

Don't connect anything to the coil. Connection should be made at the wire coming from the distributor, which is I believe a black/purple wire. You might have fried your tach and cdi. Good luck.

I don't think connecting to the + side of the coil is so bad. A lot of people get their 12v power there when using a timing light. What may have happened is simply a wire got pulled loose. kwikt is right about the black and purple wire. Look to see that it's not off the connection. IIRC, it's on the other (negative) side.

The CDI is fine if the car runs.