I've done it before on my old ford truck. But now I can't remember for sure how to do it.
I'm working on a '73 mach1 w/351, 4-speed. The ignition switch is bad. So I have to bypass it for now. I can jump it from the solenoid and it turns over fine. But since my ignition switch doesn't work I won't get any spark from the coil. I can't remember how to by pass the circuit for the coil. I thought that I just had to jumper a 12-volt circuit to the coil but I didn't want to burn anything up. So I figured I use someone else's memory. Anybody got some pointers???????????

 

Use a wire at least 10 guage from positive side of battery to positive side of coil, smaller wire gets hot real fast and can melt and cause a short since the cars frame etc is a ground, short out solenoid on firewall, positive battery cable to starter side of solenoid, should start, this is only recommended for troubleshooting, if you get pulled over you will have to explain why the car is "hot wired"

 

That's what I tried. I thought you just had to hook up a 12-volt circuit to the coil. But the coil must be bad.
I won't have to worry about getting pulled over in the car.... It's got no floorboards, headlights or tranny. I'm just trying to get it running for my father-in-law.
Thanks for the info.