Morris Minor Owners Club

Hi I hope that the wise people on here can help me. It might seen a silly thing to ask. First my car is an negative earth car and I have just put on an Lumenition Magnetronic ignition system MTK003 and it says for a negative earth car red wire goes to + on coil and black to - on coil. Than take away wire that came from contact breaker which was connected to which should have been the - on the coil but it was on the + on the coil and the wire from the ignition which should have been on the + was on the - on the coil. The thing I can not understand is the car ran this way. Would it be ok just to put the wire from the ignition on the + on the coil.
Thanks for any help give.

When manufactured the car would have been positive earth, and the wiring is correct for that. Whoever converted to negative earth didn't bother to swap the leads on the coil.

Coils are very forgiving and will work either way round, but are usually better the way they were intended.

Are you sure that coil is correct Ohms value for use with the Magnetronic system ?