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69 Camaro RS/SS Z28 Pertronix Relay

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2.7K views 23 replies 9 participants last post by  SY1  
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#1 ·
Ordered a relay for the coil to supply 12v to the coil full time...where are you guys mounting this relay?

It's kind of dumb they made the switch wires....ie the lowest amperage wires the shortest wires.

No where near the coil works. This is a frame off resto. I'll update the thread if I find somewhere that works that is hidden. But if not throw the ideas at me. I've spent 3 hours trying to find a spot for it. But the damn switch and ground wire are short
 
#4 ·
OP

If this is a "frame off resto", are you using the original engine bay wiring harness or aftermarket one for HEI dizzy like AAW?

All you need to do is run a #10-gauge stranded copper wire from IGN tap on fuse block to coil instead of using the white resistance wire from bulkhead connector to coil that is in the stock wire harness to get full 12VDC

No relay needed. Been using Pertronics kits in stock dizzy for years in my cars
 
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#5 · (Edited)
I ended up mounting the relay in the fender wheel near battery. I wrapped all the wires much like the factory harness already on here. So the change is minimal.

Easier ways to do it are relative. The original harness has been installed and wrapped so putting another wire in that harness to where it can't be seen would be more trouble than it's worth
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#12 ·
Curious what issue are you having that led you to install an independent 12V power source via a relay? Is it to limit the ignition switch run position current using the switch only as control voltage for the relay? I run a Pertronix II on my 68, wired like the instructions showed, so far so good. Green wire is my tach. Cool 69 btw(y)
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#13 ·
Is this where all the crossram guys hang out? I have the same Pertronix Igniter 3 in my car, is it better to use the relay or 12v ignition on power to the coil? The relay wires up to the coil, battery, ground, and where’s the 4th wire go @STI_MECE ?

Just getting around to buttoning up the engine swap, had a front freezer plug that kept weeping after it warmed up.
 

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#16 ·
Thanks all for the nice comments on the car...

This 69 is still running the Delco coil, I believe the wireset was changed to 7mm magnecore wires. @ctap3, the 4th wire is the switch for the relay to close the signal between the constant 12v source and the coil. For the switch wire, I used the resistor white wire (it has some sheathing on the outside of it) that is coming from the.....i forgot where it's coming from I think its tied into the ignition switch circuit where it will supply votlage to the coil (but the wire by design doesnt allow full 12v because its designed to be a resistor). But that is the wire I believe most guys replace with a regular wire capable of sustaining higher amperage than what its designed to handle. In all honesty, I would have gone that way but everything is wrapped up in tape, and I am not going to be pulling that stuff out to run that. I wanted to pull that wire running between the starter and the coil but again...that is wrapped up now.
 
#18 ·
IMHO, simply unwrapping the engine bay wire harness from firewall side of bulkhead connector to coil that runs along the trough on firewall to add or replace the white resistance wire is WAY simpler and cleaner (read original looking also) than installing a relay somewhere to get full 12vdc to the coil for Pertronix

You can also unpin the white resistor wire from bulkhead connector and pin in a new #10 stranded copper wire, even white in color, to replace the white resistance wire for a uber clean looking (original) wiring setup.

I chose to just tape back the original white resistor wire and run a new one within the wire harness that originates from the IGN tab on fuse block.
 
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#19 ·
@SoCal805, agreed. I can always change it later. I did a non destructive install so I could roll everything back before if I needed to.

In terms of wiring...where do you guys like to shop for your non insulated connections for cars like this? And one thing I liked on this harness, is that some of the terminal connections have this nice rubbery thick sleeve over the non insulated terminal. Its like heat shrink, but it still stays supple, and and its pretty thick, maybe 1/16" thick? I use flame retardent loom on other modern builds. But some of this stuff would help if it had a fire braided sheathing around it or something. I am always looking to expand the type of electrical bits I stock.
 
#20 ·
Del City is one source for electrical connectors and may have the thicker heat shrink you mention.

I prefer and use split loom over wire harness. I am not a "has to look original" person but understand some builds like Op's Z would warrant staying original looking.

I buy flame resistant (blue stripe) and heat resistant (grey stripe) split loom online in 100' rolls of various sizes for my car wiring projects. The cheap plastic stuff sold at auto part stores has no business under hood or chassis.
 
#21 ·
I use the ashphalt cloth braided wire loom on my engine compartment small component leads that aren't the vinyl wrapped or had been cut open, like alternator, coil & distributor wires. Available in many diameters and really inexpensive. Found on ebay.
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I tried friction and/or 3M electrical tape at the ends by the components, but not happy with the results. So my fusion tape is next. Fusion tape is a thicker rubber tape that when you wrap it, pulling it very tightly it stretchs and fuses to itself, result is weather tight. You want the smooth rubbery style. The textured harder surface style doesnt work so well. Ideally when stretching and wrapping the white line is the target to overlay and if you do it right you dont see the white guide line. I doubled back to fuse the the end and you end up seeing the line at the end, but most secure way to end the wrap.
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The AMP vendor supplied us with it when I was working heavy jet aircraft, same with the terminals. Be careful when ordering the clear boots for your female or male spade terminals, some are the soft rubber, some hard plastic like the blue one, both work, but make sure you get what you want.
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#22 ·
Nice! Thanks for sharing yall's sources! I too use modern fire retarded loom for most of my work. And I have some non adhesive looking vinyl tape thats great for harness work when it has to be wrapped. I am a stickler for my electrical connections...I go as far as purchasing SAE publications on what is considered standard for the OEM manufacture design. I too have found, you can have two terminals look the exact same but that material quality can be completely different and one will screw you and one wont.

If I am bored, im going to look for that resistor wire and try and get that braided sleeve for it and ill put ill upwrap that harness when I have time again. I got a 70 chevelle with a 454 now to fix. Its popping on left turns only.
 
#24 ·
Good plan. I alway hate cutting into nicely OEM wrapped harnesses, but it is real important to have the full 12 volt minimum on the ignition system. Pertronix has a lot of info on this. I don't know the specs on the Delco coil, but I do know the Petronix III system was designed to be used with an exclusive low resistance coil, 0.32 ohms. Petronix II uses 3.0 ohms on V8 installations and can use the 1.5 ohm on race only they claim. The P III low coil resistance they state shortens the recovery time for the coil for high rpm use. Definitely a bonus for the 302 and your 8K shifts;).
 
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