Author Topic: Pertronix 3 wiring?  (Read 7368 times)

Kent

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Pertronix 3 wiring?
« on: April 19, 2020, 03:11:28 PM »
I have a question, I dont want to destroy the tach on my gt500, what do I have to do when wiring the Pertronix 3? Thanks for the help.
SAAC Member from Germany and Owner of a unrestored 1967 Shelby GT500, 1968 1/2 Cobra Jet´s and some nice Mustang Fastback´s 67/68

S7MS427

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Re: Pertronix 3 wiring?
« Reply #1 on: April 19, 2020, 06:49:46 PM »
I wired mine up per the Pertronix supplied instruction sheet.  Tach works fine.  Others may have differing opinions.
Roy Simkins
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The Going Thing

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Re: Pertronix 3 wiring?
« Reply #2 on: April 19, 2020, 11:43:41 PM »
The II and III will not work as per Pertronix.

oldcanuck

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Re: Pertronix 3 wiring?
« Reply #3 on: April 20, 2020, 09:13:11 AM »
After my conversion, my tach seems to be reading about 200-300 rpm low.....
Bob
Knoxvegas, TN

Royce Peterson

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Re: Pertronix 3 wiring?
« Reply #4 on: April 20, 2020, 09:21:44 AM »
The Pertronix device should not cause that if it is wired properly. One other thing can cause the tach to read low or high is using a coil with incorrect resistance. The tach detects current to give accurate RPM. If the coil is lower or higher resistance than stock then the tachometer cannot detect the proper current.


After my conversion, my tach seems to be reading about 200-300 rpm low.....
1968 Cougar XR-7 GT-E 427 Side Oiler C6 3.50 Detroit Locker
1968 1/2 Cougar XR-7 428CJ Ram Air C6 3.91 Traction Lock

oldcanuck

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Re: Pertronix 3 wiring?
« Reply #5 on: April 20, 2020, 09:47:03 AM »
I wired per the instructions, but I replaced the old non-original coil with a new Pertronix Flame Thrower coil as I thought that is what was required for the HEI ?

Is that were I goofed....... ?
Bob
Knoxvegas, TN

Royce Peterson

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Re: Pertronix 3 wiring?
« Reply #6 on: April 20, 2020, 12:40:59 PM »
Yes indeed. The Pertronics coil is lower resistance than the stock coil. So it gives a higher output to the plugs but ruins the performance of the tachometer.

Personally I prefer using the stock yellow top coils.

I wired per the instructions, but I replaced the old non-original coil with a new Pertronix Flame Thrower coil as I thought that is what was required for the HEI ?

Is that were I goofed....... ?
1968 Cougar XR-7 GT-E 427 Side Oiler C6 3.50 Detroit Locker
1968 1/2 Cougar XR-7 428CJ Ram Air C6 3.91 Traction Lock

The Going Thing

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Re: Pertronix 3 wiring?
« Reply #7 on: April 20, 2020, 02:16:53 PM »
Despite the information given here, the Pertronix II and III will not function as wired by ford with the tach. Not an assuption, but fact.  It MUST have a 12V power source to the module. Even the Pertronx I require it, despite them running... For a while. I have a Shelby with a factory tach and have been through this.
The diagram Pertronix supplies is NOT Mustang specific and is wrong. It's why I keep talking to people in messages and giving them instructions to walk them through.  The II and III will damage a factory tach without proper wiring. 
Many wind up getting talked into a three-wire tach movement when they don't need it because of this. 

Royce Peterson

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Re: Pertronix 3 wiring?
« Reply #8 on: April 20, 2020, 02:39:54 PM »
I completely reject your opinion.


Despite the information given here, the Pertronix II and III will not function as wired by ford with the tach. Not an assuption, but fact.  It MUST have a 12V power source to the module. Even the Pertronx I require it, despite them running... For a while. I have a Shelby with a factory tach and have been through this.
The diagram Pertronix supplies is NOT Mustang specific and is wrong. It's why I keep talking to people in messages and giving them instructions to walk them through.  The II and III will damage a factory tach without proper wiring. 
Many wind up getting talked into a three-wire tach movement when they don't need it because of this.
1968 Cougar XR-7 GT-E 427 Side Oiler C6 3.50 Detroit Locker
1968 1/2 Cougar XR-7 428CJ Ram Air C6 3.91 Traction Lock

The Going Thing

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Re: Pertronix 3 wiring?
« Reply #9 on: April 20, 2020, 02:47:38 PM »
I really could care less what your opinion is. You're wrong and I have an original tach car and at least seven people here who corrected their issue with my help.
It's not a guess, it's an issue that even Pertronix was given information to correct their generic tach wiring instructions which don't work. Phil Severance also recommends the same method I use. If you wire a Pertronix II direct they are several hundred RPM off.
Your BS and know it all attitude is why I stopped posting the information openly. I'm sorry your ego is bruised.

Royce Peterson

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Re: Pertronix 3 wiring?
« Reply #10 on: April 20, 2020, 03:04:08 PM »
I've been installing and using Pertronix devices since the early 1990's and have never had one fail or anything happen to a factory tachometer as a result. You are simply either unable to read schematics properly or you don't have good information at your disposal.

Here is a simplified schematic of how to properly wire an original Pertronix or the Pertronix II in our cars.


I really could care less what your opinion is. You're wrong and I have an original tach car and at least seven people here who corrected their issue with my help.
It's not a guess, it's an issue that even Pertronix was given information to correct their generic tach wiring instructions which don't work. Phil Severance also recommends the same method I use. If you wire a Pertronix II direct they are several hundred RPM off.
Your BS and know it all attitude is why I stopped posting the information openly. I'm sorry your ego is bruised.
1968 Cougar XR-7 GT-E 427 Side Oiler C6 3.50 Detroit Locker
1968 1/2 Cougar XR-7 428CJ Ram Air C6 3.91 Traction Lock

The Going Thing

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Re: Pertronix 3 wiring?
« Reply #11 on: April 20, 2020, 03:07:53 PM »
There's a much easier way to do it.   That is the crap that Pertronix hands out.  I'll just keep helping people fix the issue at hand.

Royce Peterson

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Re: Pertronix 3 wiring?
« Reply #12 on: April 20, 2020, 03:13:40 PM »
Actually the drawing was done by a friend of mine because the Pertronics information is so hard to follow. Again you are making generalizations that are incorrect.

When the drawing was made he placed the word Resistor on both wires coming to and going from the coil. The one on the left should not be there.


There's a much easier way to do it.   That is the crap that Pertronix hands out.  I'll just keep helping people fix the issue at hand.
1968 Cougar XR-7 GT-E 427 Side Oiler C6 3.50 Detroit Locker
1968 1/2 Cougar XR-7 428CJ Ram Air C6 3.91 Traction Lock

The Going Thing

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Re: Pertronix 3 wiring?
« Reply #13 on: April 20, 2020, 05:42:38 PM »
My method takes about an hour and there are zero permanent changes to the factory harness. It works and has for several here.
It's clean, the tach works correctly afterward and the Pertonix doesn't fail. Six feet of 14 gauge wire, a male and female bullet connector and a Scotchok and is easily and completely reversible. 

67gt500

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Re: Pertronix 3 wiring?
« Reply #14 on: April 20, 2020, 08:52:33 PM »
I had a old loom around, so I did a mock up of how or where to splice the new 12 V wire that runs out to the Pertronix.. Splice is done on the red / green stripe wire..
“The going thing” is this how you did yours ?