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Old Mar 15, 2013 | 09:44 PM
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installing hei on my 74. to get the full 12v i was gunna run a wire to ign on fuse panel but it is occupied by a black and pink wire. can i just scotchlok into this? it already has was appears to be a factory splice of a male connector on it.
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Old Mar 15, 2013 | 10:09 PM
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Hi nomomopars,
(On my 74) I found 12v for my HEI on the seatbelt interlock bypass (If you still have it).
See link if you don't know what I'm talking about.
It worked for me PLUS it's close to the dizzy- so you can use shorter wires.
Cheers,
Gav
http://forums.corvetteforum.com/c3-g...-firewall.html

Last edited by thegavel; Mar 15, 2013 at 10:11 PM.
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Old Mar 15, 2013 | 10:09 PM
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I have a 74 also and happily made the same HEI conversion. If the wire you are holding is black with pink letters that say "Resistor" (or something to that effect" then that is the wire you are trying to replace.

Its been a long time since I did this but it went something like this...
I followed the resistor wire back to the fuse block bulk head connector. This is where I get fuzzy if it was a male of female connector, but went like this. I used a soldering iron to heat up the connector in the plastic bulk head connector and it realesed from the plastic. the heat made it slide out easy.

Then I got a new wire with the same type connector installed on the end and held a lighter to the connector to get it nice and hot. I slid right into the place of the old connector and cooled into place nicely.

Its just an idea. I know its not very clear but if you follow that resistor wire to its end it should make a little more sense. You have probably already found a MUCH easier way to do this...

Have fun.
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Old Mar 15, 2013 | 11:09 PM
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Is converting to hei a performance upgrade ?? I still have the original ignition on my 74 but have seen a few posts about this. What's the benefits
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Old Mar 16, 2013 | 06:39 AM
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Hotter spark, no more points/condensers to replace,etc.
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Old Mar 16, 2013 | 07:08 AM
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Originally Posted by thegavel
Hi nomomopars,
(On my 74) I found 12v for my HEI on the seatbelt interlock bypass (If you still have it).
See link if you don't know what I'm talking about.
It worked for me PLUS it's close to the dizzy- so you can use shorter wires.
Cheers,
Gav
http://forums.corvetteforum.com/c3-g...-firewall.html
seatbelt relay is long gone.
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Old Mar 16, 2013 | 07:11 AM
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Originally Posted by johnt365
I have a 74 also and happily made the same HEI conversion. If the wire you are holding is black with pink letters that say "Resistor" (or something to that effect" then that is the wire you are trying to replace.

Its been a long time since I did this but it went something like this...
I followed the resistor wire back to the fuse block bulk head connector. This is where I get fuzzy if it was a male of female connector, but went like this. I used a soldering iron to heat up the connector in the plastic bulk head connector and it realesed from the plastic. the heat made it slide out easy.

Then I got a new wire with the same type connector installed on the end and held a lighter to the connector to get it nice and hot. I slid right into the place of the old connector and cooled into place nicely.

Its just an idea. I know its not very clear but if you follow that resistor wire to its end it should make a little more sense. You have probably already found a MUCH easier way to do this...

Have fun.
i thought this wire i am talkin bout was the power windows. it is the wire at the fuse panel, pink with black stripe no letters
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Old Mar 16, 2013 | 09:35 AM
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I am sorry if I confused the issue. Yes, sounds like you are working with wires under the dash. I was proposing another option that involved replacing the original resistor wire with a full 12v capable wire.
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Old Mar 16, 2013 | 10:20 AM
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I wouldn't use the power window wire - when you use the power window, the performance of your motor will go down (and possibly shut the engine off). Not to mention, the power windows don't operate when the ignition is in the "start" position... if you wire your distributor to that wire, your car won't start (it might if the engine is still spinning when you release the key... trust me, it's an annoying diagnosis the first time it happens).

Replace the original resistor wire with a non-resistor wire. Otherwise, there is an port on the fuse panel that is hot at all the right times.. IIRC it's the top open plug on the fuse block (at least it is on my 77 panel).
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Old Mar 16, 2013 | 12:00 PM
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what about the "batt" terminal on the fuse panel?
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Old Mar 16, 2013 | 12:09 PM
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Originally Posted by redwhitekat
Is converting to hei a performance upgrade ??
No. No performance increase.
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Old Mar 16, 2013 | 12:48 PM
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I am in the process of doing a complete rewire with HEI upgrade.

I have all new harnesses and replacing the resistor wire would be nice. However, I am scared to use heat for fear of warping the connector block.

What about using the Alternator (pin 2) 20ga brown Ign On wire?

Would this provide enough power for both?
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Old Mar 16, 2013 | 06:08 PM
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What you could do is use a relay mounted in the engine compartment and pull a full 12 volts from back of the alternator for your "power in " (fused) relay wire and the power out side of the relay going to the HEI. Then use one of the other smaller relay wires as the trigger wire and run that to your brown wire location or any other ignition on source. The other wire on the relay goes to a good ground. Always nice to have a clean 12volt source when dealing with old wiring and it does not take much voltage to trigger the relay, only about 8 volts if I recall.
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Old Mar 16, 2013 | 07:11 PM
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Originally Posted by Mike Ward
No. No performance increase.
LOL

really?!! have you ever changed from points to an HEI? As someone who has changed from points to HEI, getting 10x hotter spark has a marked performance, and mpg increase.
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Old Mar 16, 2013 | 07:19 PM
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Originally Posted by wilcar
What you could do is use a relay mounted in the engine compartment and pull a full 12 volts from back of the alternator for your "power in " (fused) relay wire and the power out side of the relay going to the HEI. Then use one of the other smaller relay wires as the trigger wire and run that to your brown wire location or any other ignition on source. The other wire on the relay goes to a good ground. Always nice to have a clean 12volt source when dealing with old wiring and it does not take much voltage to trigger the relay, only about 8 volts if I recall.
what if i put the power window plugs to the acc position on the fuse panel then i could run the wire to ign position
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Old Mar 16, 2013 | 07:21 PM
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Originally Posted by SuperBuickGuy
LOL

really?!! have you ever changed from points to an HEI? As someone who has changed from points to HEI, getting 10x hotter spark has a marked performance, and mpg increase.
And I'm sure your grill cooks steaks faster depending on whether you light it with a match or a spark.
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Old Mar 16, 2013 | 09:54 PM
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Just use the same wire (the resistor wire) that goes to the coil. BUT, tap into it near the fuse block and run another lenth of #14 or #12 awg wire up to the coil. That will be the new "12vdc feed wire". Wind up the unused portion of the 'resistor wire', cap off the open end of it, and tie-wrap it up somewhere low on the firewall. Then it will be there if you ever decide (or need) to wire it like the factory did.
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Old Mar 16, 2013 | 10:44 PM
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Originally Posted by Mike Ward
And I'm sure your grill cooks steaks faster depending on whether you light it with a match or a spark.
if the match blows out - it doesn't light at all

really, stop now...
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Old Mar 16, 2013 | 10:55 PM
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In the center of the firewall connector is a bolt, loosen the bolt and the whole connector will come off, then you can release the terminal and reinsert one with the non resister wire. Here is what the connector looks like, just push the barb over and pull it out.
Item picture

http://www.ebay.com/itm/121020621279...84.m1423.l2649

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Old Mar 16, 2013 | 11:22 PM
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Originally Posted by Mike Ward
No. No performance increase.
Lars agrees w/ Mike Ward on this one. I personally would run HEI for maintenance (I'm a lazy ***), but aside from that...
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