I seem to remember a recent thread on Pertronics but can't locate it. Is is a convenient 12v switched power source in the engine bay for a pertronics install?
Thank you
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It's a simple install. It comes with directions. I have about 5000 miles on mine with no problems.
Thank you, yes, I understand as I run Pertronix on a few other cars. Looking for an easy 12v source on a P car...
You can just use the power going to the coil.
Forest
Forest
One of the issues with a Pertronix is that it is recommended to use a full switched 12v source. In a Ford car of the same era, If you test the wire connected to the coil AND connected to the Pertronic module with engine off, the voltage tests only about 5-6 volts. You'll note that Pertronix claims the units will operate from 6-16 VDC, so the car's voltage is right on the low end of the scale. I'm assuming a Pantera is the same (??). I've seen cars run for years that way with no problem, others have issues with the low voltage. Did a 72 car have a carb solenoid, I don't see it on the prints I have. That would be a good switched source...
Answered my own question, I'm used to cars of this vintage having a resistance wire stepping the voltage down to the coil, I should be able to just tap into the 12v source that feeds the resistor mounted on the bulkhead..
John,
the light blue wire supplying the coil from the ignition switch does incorporate a section of resistance wire.
I always advise installation of a relay to supply any sort of high current ignition, to prevent that current from passing through the ignition switch.
Your friend on the DTBB
the light blue wire supplying the coil from the ignition switch does incorporate a section of resistance wire.
I always advise installation of a relay to supply any sort of high current ignition, to prevent that current from passing through the ignition switch.
Your friend on the DTBB
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quote:
I always advise installation of a relay to supply any sort of high current ignition, to prevent that current from passing through the ignition switch.
Or... insert an inline fuse between the 12v source (that feeds the resistor) running to the pertronix?? Perhaps an 8 amp fuse, I'll contact Pertronix ad see wha their unit draws and go from there.,.
Thank you
John
The 12 volt source to your ignition must be switched in one way or another, either with a relay or via the ignition switch. The idea is to avoid using the ignition switch, as the contacts will fail when used to conduct heavy currents, and the switches are hard to come by and expensive.
your friend on the DTBB
your friend on the DTBB
Thanks George.
And please put up a pic of a beautiful woman on your avitar, the current one scares me.. LOL
And please put up a pic of a beautiful woman on your avitar, the current one scares me.. LOL
quote:Originally posted by george pence:
John,
the light blue wire supplying the coil from the ignition switch does incorporate a section of resistance wire.
I always advise installation of a relay to supply any sort of high current ignition, to prevent that current from passing through the ignition switch.
Your friend on the DTBB
George, is the light blue wire that feeds #86 before the stock resistor or does it come out of the resistor and feed the + side of the coil?
Thanks
John
John,
there is no resistor. the wire itself is the resistance. Its a special type of wire designed for that purpose. From ignition switch to coil, the wire provides the needed resistance of approximately 1.5 ohms. The relay coil is approximately 73 ohms, so the voltage drop across the resistance wire is 0.27 volts, and across the coil of the relay the voltage drop is 13.38 volts (assuming a 13.65 volt system) which is sufficient to activate the relay coil.
Just hook the light blue wire to terminal 86 of the relay, terminal 85 to ground. If your new ignition requires a resistance, you'll hook a new resistor between terminal 87 and the new ignition.
your friend on the DIC
there is no resistor. the wire itself is the resistance. Its a special type of wire designed for that purpose. From ignition switch to coil, the wire provides the needed resistance of approximately 1.5 ohms. The relay coil is approximately 73 ohms, so the voltage drop across the resistance wire is 0.27 volts, and across the coil of the relay the voltage drop is 13.38 volts (assuming a 13.65 volt system) which is sufficient to activate the relay coil.
Just hook the light blue wire to terminal 86 of the relay, terminal 85 to ground. If your new ignition requires a resistance, you'll hook a new resistor between terminal 87 and the new ignition.
your friend on the DIC
Thanks George, I realize that most Ford cars of that era have a resistance wire, generally the infamous 'pink' wire under the dash. My '72 has a ballast resistor mounted between the voltage regulator and the coil, I assumed it was stock. So it sounds as though I should trigger the relay with the blue wire (shown in the 3-wire bundle) as it enters the ballast resistor as opposed to the ballast resistor's output feeding the coil, ?? Wondering if it might be a bit safer to use the output of the resistor (feeding the coil) to trigger the relay) Again, thank you..
John,
there's nothing to be gained by keeping a resistance in the coil circuit of a relay, safety or otherwise.
However, the light blue wire landed on the coil is the ignition resistance wire, and it is not connected to the resister in the picture. The resister is in the voltage regulator circuit, it is there to provide an activation point for the battery discharge lamp located on the speedometer's face, that lamp connects to either side of the resistor.
Like I've written before, a pic is worth a thousand words.
your friend on the DIC
there's nothing to be gained by keeping a resistance in the coil circuit of a relay, safety or otherwise.
However, the light blue wire landed on the coil is the ignition resistance wire, and it is not connected to the resister in the picture. The resister is in the voltage regulator circuit, it is there to provide an activation point for the battery discharge lamp located on the speedometer's face, that lamp connects to either side of the resistor.
Like I've written before, a pic is worth a thousand words.
your friend on the DIC
George, I added a drawing to the picture above. Both wires connected to the coil are connected to the bottom (right and left) of the resistor. The (-) side is blue and the 'Bat' side appears to be green with a red stripe, but very hard to tell. All wires in that area have the same patina. The large black wire coming out of the moldex connector is about the same size as the lead going to the distributor, so I assume that what it is. Perhaps that blue wire adjacent to it feeds the tach. The red wire going to the moldex connector is the thinest in the group. Back to my original question, suggestions on what to use to trigger the relay? Just come right off the 'bat' side of the coil? The car is a pre-L '72. Again, thanks for your patience..
John
John
Sorry John, my mistake, I saw the light blue on the one wire attached to the coil and I thought I was looking at a late model engine bay.
Your early car does not employ a resistance wire in the ignition circuit. It uses a "dual" ballast resistor.
That's the convoluted thing about the early cars, that dual resistor module, one resistor is in line with the power from the ignition switch to the positive terminal of the coil (note the "red" wire is the power from the ignition switch). The other resistor is in line with the wiring between the negative terminal of the coil and the points. I have no idea why the resistance was split up like that.
Remove the red wire from the resistor (its actually a pink wire that has darkened from the engine compartment heat) and connect it to your new relay. Unless you plan on using this resistor for something, remove it and file it in the round file.
The blue wire with black stripe that threw me off earlier, thats the wire going to the tach, you'll need to reattach it to your new coil's negative terminal, unless you're installing a multi-spark ignition.
Your friend on the DIC
Your early car does not employ a resistance wire in the ignition circuit. It uses a "dual" ballast resistor.
That's the convoluted thing about the early cars, that dual resistor module, one resistor is in line with the power from the ignition switch to the positive terminal of the coil (note the "red" wire is the power from the ignition switch). The other resistor is in line with the wiring between the negative terminal of the coil and the points. I have no idea why the resistance was split up like that.
Remove the red wire from the resistor (its actually a pink wire that has darkened from the engine compartment heat) and connect it to your new relay. Unless you plan on using this resistor for something, remove it and file it in the round file.
The blue wire with black stripe that threw me off earlier, thats the wire going to the tach, you'll need to reattach it to your new coil's negative terminal, unless you're installing a multi-spark ignition.
Your friend on the DIC
quote:Originally posted by topcat:
It's a simple install. It comes with directions. I have about 5000 miles on mine with no problems.
I just did one of these installs. Use the relay just as the diagram shows.
It works great.
It works great.