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Converting to 12V ignition


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Hi folks,

I have a 71 and am trying to convert from a points ignition to an electric ignition. I have a pertronix flamethrower distributor however it appears that it requires 12V input at the coil. I checked voltage on the coil and as expected it is 6V due to the online resistor. Is it possible to use a voltage step up such as https://www.amazon.com/dp/B01L90B3RI/ to get to the 12V or do I have to run a wire through the firewall and replace the ignition switch wire in the column? (Or something else of course.)

I’m definitively concerned with something as critical as the ignition system using something like that since if something goes bad with it (and it will get continual use) then it won’t run. However someone had mentioned the idea at the local car shop and not running a new wire through the firewall, dropping the column, etc, has a some real appeal to it.

Does anyone have experience with this and/or strong opinions on if this a good or bad idea?

Thanks,

David

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Yes you definitely need 12 volts for that system to work. They say to run a regular wire from ignition switch to coil as opposed to the register wire that is there. I no longer use the throttle selanoid so I got my voltage from that wire.  As long as you have 12 volts with key on it will work but you can not have constant voltage. The pertronix tech guys were great to work with very helpful don't be afraid to call them and ask questions. 

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43 minutes ago, cny first gen 71 said:

Yes you definitely need 12 volts for that system to work. They say to run a regular wire from ignition switch to coil as opposed to the register wire that is there. I no longer use the throttle selanoid so I got my voltage from that wire.  As long as you have 12 volts with key on it will work but you can not have constant voltage. The pertronix tech guys were great to work with very helpful don't be afraid to call them and ask questions. 

Do you have pics of the throttle solenoid or where it’d be located? From what I read it was kinda put in place for helping with AC power draws or something similar. AC was taken out of this system so it might be free.

Also this has a non-stock edelbrock 4-barrel carb so not sure what may or may not still be in use. 

I called pertronix and their recommendation was to just replace the wire from the ignition switch, so I think the booster is out (what I assumed would probably be the right choice). Anything else a candidate in the engine compartment? I tested a few random relays in the compartment but nothing registered in run mode. (A lot of this has had the engine painted so might be I could scrape some paint.)

Thanks,

David

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Should be a 2 wire plug possible laying on intake manifold the solenoid was on drivers side of original carb. Maybe someone cut the wires when they put aftermarket carb on. Don't really remember the color of the live wire. The second one was a ground. For me it was just easier using that wire than running a new one. Shouldn't be a big deal just find the correct wire cut it off and run a non resistor wire. 

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Good question; the wipers work but never tried the washer. (And the resivoir is old and crusty, so assume they pulled the washer pump out along with the AC.) based on the fact that it has extra instrument panel inside, headers instead of exhaust,  aftermarket cab and missing AC would assume the guy I got it from was trying to hotrod it and cleared the unnecessary parts out for space, but don’t really have any vehicle history. 

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That is the washer pump plug. The washer pump is bolted to the wiper motor. But there are no terminals on the pump. Hmmm. No hoses hooked to the pump either. I would save that one to fix the washer pump. Do it once, and correct. Run the new wire to the ignition switch. 

DB132D4D-16CC-4C25-B70C-768195A355B2.jpeg

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So I ended up doing some more research and Pertronix has a relay kit that takes the 6V from the old ignition switch wire and the 12V battery in and uses that as a switch to provide 12V when the ignition is on. For the life of me I don’t know why the person I talked to earlier there didn’t suggest that as a solution. So I think I get a best of both worlds here.

https://pertronixbrands.com/products/pertronix-2001-ignition-power-relay-kit

I will report back after I get and install it but definitely sounds like something in the direction I’m looking for, made expressly for this purpose. 
 

David

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This is my first real project car so I’m getting my feet wet at the pace I’m comfortable with. If there’s something in the engine compartment I could tap into I’m all ears, just felt like taking the whole column apart so I could get to the switch wires was a little more than I wanted to if there were alternatives. Don’t mind spending a little money on it. 

Cheers,

David

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Don't think you have to take it apart, the ignition switch is mounted to the lower column just have to find the proper wire. I guess I should have said welcome to the site before this but welcome aboard.  You will find a lot of help here there's always someone that's done it before.  Oh yea we love pictures too.

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David, 

I went to the fuse panel under the dash (drivers side next to steering column) with a wire and 15 Amp inline fuse. Plugged it in the switch side of the ignition and ran it to thru the firewall to the HEI distributer.. Really simple… 

If you look closely , you may find a predrilled hole in the firewall.. I drilled a hole in mine  way back in the 1980's. I use after market gages and use the hole for everything I need... 

Be sure to use an inline fuse and a grommet in the hole you choose route the wire thru.

Welcome to the club David. 

Ed..  

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David

Also, this may help….

Over the years I've added a lot of accessories and I always route the power directly to the main fuse block ...

ie :  automatic door locks that work like the new cars with alarm system and key fob… 

Back up camera..

trailer hitch with tail lights and turn signal hook ups… 

I never tap an existing wire for anything… 

To the horrors of our purest friends , you can see the camera near the Monte script … It is needed for my wife so she can drive and enjoy the car as well...

Ed ...

819488870_IMG_25322copy.thumb.jpeg.0de1d685a4a35bb90d13b0ae84ddf1f9.jpeg

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How about the spade connector in the fuse block that says ign. And run a wire from there to the coil. I believe that is where I have 4 out of 6 of mine. 

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If I'm not mistaken the original voltage to your stock points distruster should about 9 or 10 volts … These original wires are routed thru starter and no longer needed.. I just folded them up and stuck them in the wire tray near the wiper motor.. If you connect them you will blow the new in line fuse when you least expect… 

This happened to me when I made my conversion… I was told by an idiot to keep the brown wire connected.. I had to figure it out on a hot day during a road trip…

Hope that makes sense.. 

Ed. 

IMG_2665.thumb.JPG.0bf592097b4ab7d16b797b00f997cb07.JPG

 

 

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33 minutes ago, MC1of80 said:

How about the spade connector in the fuse block that says ign. And run a wire from there to the coil. I believe that is where I have 4 out of 6 of mine. 

Yep .

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Thanks, good advice all around.  I appreciate how helpful you all have been, and am sure I will have any number of other questions, so it’s nice to have a forum dedicated exactly to your specific car. Even the chassis manual covers several models and nothing beats being able to ask questions from people with experience.

David

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On 6/16/2022 at 11:47 PM, EVC said:

Yep .

thats the best way   full 12v only when ign is on...from fuseblock thru firewall to coil...  there was also some talk about using at least a 12 guage stranded wire since even tho the hei is a short duration pulse it is hi power and you dont want instantanious voltage drop when it fires  ????

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On 6/16/2022 at 10:13 PM, MC1of80 said:

How about the spade connector in the fuse block that says ign. And run a wire from there to the coil. I believe that is where I have 4 out of 6 of mine. 

So I assume this is it:

image.thumb.png.e62c7580505076892096d56e3250748e.png

Would I just replace what is there with the new wire, or do I need to squeeze it in with the existing connections? (Looks like someone has done some other wiring changes here to go to some other instruments, but for now just focusing on this part.

I did try a relay kit to get 12V from the battery with the ballast wire as the feeder, but before I turned things on after getting everything adjusted it was reading 12V at the coil without the key on, so something isn't quite right with that setup, so might go back to this approach.  I did notice that the ballast wire included two wires though, ended up just twisting them together since it looked like that had been how the original end had been attached, but now I am wondering if one of them is constant voltage and the other was only hot when run, so might end up detaching the wire and checking voltage for each independently.

The relay kit did include a diode to prevent voltage backflow in some cases, which could also be what is at play (though from the docs it seems less than clear where this is supposed to go); at this point though I'm inclined to go with the original advice and just run the wire through the firewall as originally suggested. See, I get there eventually! 🙂

Anyway, checking out the options from where I currently stand. Thanks as always for good info.

Best,

David

 

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Actually, turns out this one was user error.  I'd not reattached the negative battery cable when testing the voltage, so it was showing the full 12V since I was completing the ground with the multimeter.  Looks like after reattaching and retesting, I'm getting 12V on run and 0V on off, so looks good now.

 

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