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Topic: Pertronix III install: IGN connecting wire only reads 10V not 12

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Pertronix III install: IGN connecting wire only reads 10V not 12 (1/3)
 6/21/22 10:35am
Doc4421
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Berlin, WI - USA

Vette(s):
1974 Corvette 350 V-8 T-Top


Joined: 9/1/2021
Posts: 7

Folks,

Maybe this is just me missing something (I really hope so), but in reviewing previous chat posts, the easiest way to get 12 volts to the plus side of the coil for a Pertronix install appears to be a spade plug into the IGN spot in the fuse panel and directly run wire through the firewall to the coil. That part was easy.

The hard/weird part, is that I put my multimeter on this wire for a check and found that it's only reading 10-ish volts prior to ignition. I have not started the car with this new system yet, as it's still in progress and because I don't want to destroy the Pertronix III that needs 12V to work.

It's a direct line from the panel to the coil, so I don't think there are resistor wires messing with me somewhere. Is it something that kicks up to 12 upon ignition or what else might I be missing?

Thanks in advance for the help!

 

Vince

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Re: Pertronix III install: IGN connecting wire only reads 10V not 12 (2/3)
 6/21/22 12:49pm
F4Gary
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Grapevine, TX - USA

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1972 LT-1 convertible with factory air.


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If you have an anti-dieseling solenoid on your carb, it is 12 volts.  You might tap into that.  I used that wire for my 12v electric choke as I wasn't using it for anti-dieseling or anything else.



|UPDATED|6/21/2022 9:49:40 AM (AZT)|/UPDATED|


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Re: Pertronix III install: IGN connecting wire only reads 10V not 12 (3/3)
 6/21/22 9:45pm
Adams' AppleLifetime Member
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Duncanville, TX - USA

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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


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Well...I would hafta ask, what is you battery voltage? 

The "IGN" terminal in the fusebox should be battery voltage with the key ON. If it is not, then there is likely a corroded terminal in the fusebox firewall passthru connector...fairly common problem. Could also be the ignition switch or connector.



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