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MG TD TF 1500 - Petronix Which Coil Post?

I am stumped - my 1954 mgtf has been switched to Negative ground. It has points and runs fine. The black lead on the distributor goes to SW (Positive) post on the coil. And coming from the new wirien loom the white wire goes to the CB (Negative) post on coil. I am wanting to see if the Petronix makes the car run even better. The instructions say hook the red (positive) wire to positive and the black wire to negative. Now knowing that my points black ground wire goes to the positive post, I am wondering what to do, as maybe the converting to neg ground reversed things. What post to the coil does the red Petronix Lead go?
Also if I connected the Petronix to the wrong coil post will it hurt or destroy the Petronix? Thanks, Keith
K E MURPHY

Keith,

Safest thing is to get a meter and measure the voltages to make sure. A car with points can run connected either way to the coil with only a slight bit of a performance hit, a Petronix unit (at least the older versions) can be damaged by connecting them backwards.

Gene
Gene Gillam

Kieth,
I can't help with the wiring, but if you are going to do a pionts/petronics comparison, don't change anything else ! And befor you make the change, make sure that the points are set properly.

Steve
Steve Wincze

Keith, see if http://www.ttalk.info/Tech/pertronix_igniters.htm might help. The post of your coil that the white wire is connected to will be your + terminal, where the Pertronix red wire wants to be connected. When you did the negative ground conversion you 'should have' switched the coil terminal wires. Bud
Bud Krueger

if it is not hooked up properly, one turn of the key will fry the Pertronix. ask me how I know. I have one installed for over 10 years and I love it. no points to mess with.. You do need a very good distrubutor. Jeff at Advanced Electronics does not like the Pertronix but will make you distributor new again.
TRM Maine

This thread was discussed between 12/06/2016 and 13/06/2016

MG TD TF 1500 index

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