12V conversion, COIL POLARITY?

[modela4shane]

What is the proper coil polarity for a 12 volt conversion? RED wire from switch to + or - side of coil. BLACK pig tail to + or - side of coil. I am using a new coil with internal resister so i wont have a ugly resister on the fire wall. Any thoughts will be greatly appreciated.

[Art Newland]

depends on if you car is (-) or (+) ground.

[Jim/GA]

It's not the voltage of the battery that matters, it's whether you wired that battery positive ground or negative ground.

The red wire coming from the switch needs to match the ground when connected to the coil. The black wire goes on the other side.

This is assuming you wired the car per Henry. When you deviate from Henry's design, you have to figure it out.

[modela4shane]

Thanks for the replies, the car is 12V NEGATIVE ground and wired just like Henrys design but with 12 volt negative. If i understand this correctly the red switch wire needs to go to the negative side of the coil and the short black wire goes to the positive side. Correct? Thanks for all the help.

[Patrick L.]

The primary lead to the points should be the same polarity as the battery ground.

[modela4shane]

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Thank you to all who replied.

[fordcragar]

I always considered the red wire to be the hot wire in a 12VDC negative ground system. The the negative side of the coil "-" goes to the distributor.

[Jim/GA]

Originally Posted by fordcragar

I always considered the red wire to be the hot wire in a 12VDC negative ground system.

Yea, well, me too! But that's not how Henry considered it, so you would be backwards in this case.

Henry had the red coil wire go to the key switch and then down to the distributor through the armored cable. So the red wire, as you say needs to be connected to the negative coil post on a negative ground vehicle.