Author Topic: Petronix and my Tach  (Read 766 times)

hurlbird

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Petronix and my Tach
« on: September 05, 2021, 10:22:02 AM »
read a lot on the site about pros and cons vs points... but could not quite get to the bottom line on whether or not installing petronix will impact the tachometer.  Thoughts?

Rocket

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Re: Petronix and my Tach
« Reply #1 on: September 05, 2021, 12:41:06 PM »
I had a Petronix in 550 for a while with no tach problems   Ron
Original owner of 6S550. Owned since 1967. 64,000 Miles, all body original except hood and front valance. All glass original except windshield. Still has aluminum 4 speed. Has replacement Mico.  Also own 1966 Mustang convertible. They are drivers, not trailer queens.

hurlbird

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Re: Petronix and my Tach
« Reply #2 on: September 05, 2021, 01:07:43 PM »
thanks. 550?

67350#1242

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Re: Petronix and my Tach
« Reply #3 on: September 05, 2021, 01:33:12 PM »
Should be no problem if wired correctly.  I have run pertronix I in 2 different cars for 15 years or better without a hiccup. 
The factory wiring is from ignition "run" through the tach, then through the pink resistor wire out to the + side of the coil.  Leave this circuit alone.
Do not wire the Pertronix to the + side of coil - get your switched +12V from before the tach - in fact it is easy to make a "Y" connector and install on the ignition side of the tach.  From the "Y" run a separate wire under the hood to the + side of the Pertronix.  Negative side of Pertronix to the "dist" side of coil.  Not too hard to hide the extra wire in the engine gauge feed harness.
I have always used the stock yellow top coils that require the resistor wire.  Some aftermarket coils do not need resistance in their circuit - I have no experience with using this type coil but suspect that if you mess with the tach circuit by bypassing the resistance wire you run the risk of too much current passing through the tach of course could burn up the tach or mess up the calibration.
Kurt.
67 GT350  SJ 02/01/67  Gray 4spd A/C
67 Coupe  SJ 11/16/66  White Auto A/C PDB

Bob Gaines

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Re: Petronix and my Tach
« Reply #4 on: September 05, 2021, 02:20:18 PM »
Should be no problem if wired correctly.  I have run pertronix I in 2 different cars for 15 years or better without a hiccup. 
The factory wiring is from ignition "run" through the tach, then through the pink resistor wire out to the + side of the coil.  Leave this circuit alone.
Do not wire the Pertronix to the + side of coil - get your switched +12V from before the tach - in fact it is easy to make a "Y" connector and install on the ignition side of the tach.  From the "Y" run a separate wire under the hood to the + side of the Pertronix.  Negative side of Pertronix to the "dist" side of coil.  Not too hard to hide the extra wire in the engine gauge feed harness.
I have always used the stock yellow top coils that require the resistor wire.  Some aftermarket coils do not need resistance in their circuit - I have no experience with using this type coil but suspect that if you mess with the tach circuit by bypassing the resistance wire you run the risk of too much current passing through the tach of course could burn up the tach or mess up the calibration.
Kurt.
The aftermarket coil that don't require the resistor wire typically have it built in so you can run them with or without a resistor wire . It is not the coil that typically causes a tach issue.  The important thing as you said is to get a full 12V to the pertronics module . +1 on your description of the best way to accomplish that.
« Last Edit: September 05, 2021, 02:21:53 PM by Bob Gaines »
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hurlbird

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Re: Petronix and my Tach
« Reply #5 on: September 05, 2021, 07:11:32 PM »
thanks might go this way... glad to hear i wont cook the tach.

RSOHC

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Re: Petronix and my Tach
« Reply #6 on: September 05, 2021, 07:15:59 PM »
The "Petronix 1" has less application problems than later Petronix versions.  Also, some modules just don't work.  If you have a problem, call Petronix and ask for a replacement module.

Royce Peterson

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Re: Petronix and my Tach
« Reply #7 on: September 05, 2021, 08:13:00 PM »
Agree completely - the Pertronix 1 is far superior in terms of reliability also.
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corbins

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Re: Petronix and my Tach
« Reply #8 on: September 05, 2021, 08:52:00 PM »
Pertronix 2 and 3 require their matching coils. A 12 V switched terminal on a 68 is the "c" terminal on the ignition switch I believe. They will run withless than 12 V , but don't like it :)

shelbydoug

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Re: Petronix and my Tach
« Reply #9 on: September 05, 2021, 09:16:24 PM »
The Petronix Igniter was very reliable for me but the coil wasn't. I went through three of them in a matter of three years.

Seemingly though you can't kill the Ford yellow top coil.

In my case, my car has about 22,000 original miles on it. A standard set of Ford points easily will give you 30,000 miles. It takes about 15 minutes to install a new set.

What exactly is this additional dependability that you are attempting to install in your car? In my view, that's just a fantasy. Something that Petronix is trying to convince you of?

I went back to points and the yellow top. Now, I don't need to carry an extra Igniter in the trunk just in case.  ::) You didn't know about that did you? Ask Petronix owners why they do that? ;)
« Last Edit: September 06, 2021, 09:13:37 AM by shelbydoug »
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