12 volt positive ground

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Jun 7, 2013 | 07:16 AM

#16

38 coupe

Cargo Master

Joined: Aug 2010

Posts: 2,927

Likes: 135

From: Houston

The coil will work with either polarity and produce the same voltage out. The difference is at the spark plug.

Here is a website that explains things nicely and even includes the graphite pencil test: Chicagoland MG Club:Tech Tips

Jun 7, 2013 | 07:45 AM

#17

CharlieLed

Lead Driver

Joined: Aug 2006

Posts: 8,093

Likes: 652

From: Brentwood, TN

[quote=big job;13231470]

Quote:

Originally Posted by CharlieLed

Maybe I am wrong but I have never even heard of a 12 V positive ground system. I thought that all the pos grd systems were 6 V and that they all went to neg grd when they went to 12 V.

Nope, in the commercial world this can go back into the early 1940s,
12 Volt pos. ground, and I worked on plenty of them. When we converted
the 1953 F900 (into a dump truck) that was 12 vt pos gr with 100 amp
alternator no doubt the fire body co did that. Heres another kicker,
I have origional 1959 Mark IV Continental my father bought only couple
year old. Get this its got an 80 amp "Delco System", ant that is listed
in the parts books. Optional of course. Dont think Henry would like that.
So this did exist.

Thanks for the info! I did not realize that there were 12 V systems in use that long ago...