ignition coil question

[BILLF/TRF]

I am installing a 6 volt alternator in my '31 tudor. It will have a negative ground. I have original wiring and i was wondering about how to hook up the "-" and "+" positive terminals of the coil. Does the black wire from the terminal box go to the "+" terminal on the coil and the red wire go to the "-" terminal or is it the opposite? Thanks.

 

[Ray With]

positive goes to + on the coil and - to neg.

 

[BILLF/TRF]

positive goes to + on the coil and - to neg.

So I would have to switch the wires from their original configuration (with positive ground) of black to "-" and red to "+" to the opposite when switching to negative ground?

 

[Tom Wesenberg]

It's too bad all coils don't have a + and - on them. Since your's does, then it's eay to know how to connect it. Whatever battery terminal is grounded is the same polarity on the coil that goes to the points. Negative battery ground means - on coil goes to the points.

 

[johnbuckley]

A couple of years ago I got a polarity tester ( A-12116) from Snyders. Great gadget as it saves my brain getting tied in knots and you can check everyone else's wiring at the club meet and find that approx 25% have their coil incorrectly wired!