Smoked HEI coil.

Been getting my 72 swinger going and was trying to get a blinker light on dash to work. In the process I noticed the voltmeter was only reading 10 volts. I was checking the ground when I heard a hiss and saw smoke coming out of engine compartment. Coil was smoking. Removed battery terminal and unhooked coil. Hooked battery up and back to 12 volts.

So I started looking and found my tach wire, I have under dash not not hooked up, may have been touching ground. It is an ebay hei ready to run with an e coil. Car worked fine before this. So would this take out coil? And what about hei module? Is there a way to test before anything else gets smoked?