Guys with 68 to72 vettes
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
Guys with 68 to72 vettes
I have a problem with a couple wires that go to the distributor,they both are covered in cloth and go to the distributor.I know what one of them is,its the + battery wire that goes to + on distributor,but i forgot what the other one went to.I changed over to hei .
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
Bill
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
You can not use either wire for a HEI conversion....one is a resistor wire, black typically steel wire, and the other is cloth going to the extra small terminal on the starter, takes battery power direct ot the coil for hotter sparks when starting....
you need runa heavy 10-12 ga wire from the ignition switch to the HEI direct....or get into the bulkhead connector and replace that resistor wire...
you need runa heavy 10-12 ga wire from the ignition switch to the HEI direct....or get into the bulkhead connector and replace that resistor wire...
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 2,373
Likes: 6
From: Baltimore MD
You can not use either wire for a HEI conversion....one is a resistor wire, black typically steel wire, and the other is cloth going to the extra small terminal on the starter, takes battery power direct ot the coil for hotter sparks when starting....
you need runa heavy 10-12 ga wire from the ignition switch to the HEI direct....or get into the bulkhead connector and replace that resistor wire...
you need runa heavy 10-12 ga wire from the ignition switch to the HEI direct....or get into the bulkhead connector and replace that resistor wire...
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
The other wire if I recall right goes down to the starter and provides 12 volts at startup and then the resistor wire gives around 9 volts while running not to burn up the points. When running a HEI you do not need this wire. I did not realize you were running a HEI system. Just a constant 12 volt supply as stated above is all that is needed. I have long since done away with this wire, I have not run points in years.
Tech Contributor
Joined: Jun 2004
Posts: 20,910
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
The other wire if I recall right goes down to the starter and provides 12 volts at startup and then the resistor wire gives around 9 volts while running Uh, no. not to burn up the points. When running a HEI you do not need this wire. I did not realize you were running a HEI system. Just a constant 12 volt supply as stated above is all that is needed. I have long since done away with this wire, I have not run points in years.
The HEI will run just fine at most voltages (8-12v), as long as it has a low resistance source to allow the extra current to flow into the coil. The adaptive dwell circuitry in the module will compensate for most system voltage variations.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
For about the twelth time on this forum, the ballast resistance does not magically change the nominal ignition system voltage. It is 12 volts. Always. The ballast resistance limits the current that flows through the coil. That is the only function and capability of a resistor.
The HEI will run just fine at most voltages (8-12v), as long as it has a low resistance source to allow the extra current to flow into the coil. The adaptive dwell circuitry in the module will compensate for most system voltage variations.
The HEI will run just fine at most voltages (8-12v), as long as it has a low resistance source to allow the extra current to flow into the coil. The adaptive dwell circuitry in the module will compensate for most system voltage variations.
I'm no electrical engineer by any standards but here is a quote directly from a GM manual " The primary current from the ignition switch passing through a resistance wire which lowers the voltage to approximatly 8 volts. This lower voltage provides longer contact life".
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Verdad Gallardo
Instructor
Joined: Feb 2007
Posts: 114
Likes: 18
From: McKinney TX
For What It's Worth
There's a difference between voltage and voltage drop. In a 12V automotive circuit the voltage at any point in that circuit is 12V, but the drop at each point of resistance (such as the points and/or resistor) varies depending on the resistance of the other points of resistance.
In short, if the points were the only point of resistance, they would see a full 12V drop but by adding resistance in line the drop at the points is reduced.
--> We should run a survey on the other forums to see how many people even know what points are!
In short, if the points were the only point of resistance, they would see a full 12V drop but by adding resistance in line the drop at the points is reduced.
--> We should run a survey on the other forums to see how many people even know what points are!
Melting Slicks
Joined: Mar 2005
Posts: 2,187
Likes: 7
From: Chetwynd B.C.
There's a difference between voltage and voltage drop. In a 12V automotive circuit the voltage at any point in that circuit is 12V, but the drop at each point of resistance (such as the points and/or resistor) varies depending on the resistance of the other points of resistance.
In short, if the points were the only point of resistance, they would see a full 12V drop but by adding resistance in line the drop at the points is reduced.
--> We should run a survey on the other forums to see how many people even know what points are!
In short, if the points were the only point of resistance, they would see a full 12V drop but by adding resistance in line the drop at the points is reduced.
--> We should run a survey on the other forums to see how many people even know what points are!
I would think about 3%
shmoky
Burning Brakes
Joined: Jan 2007
Posts: 1,057
Likes: 4
From: Concord Calif
All trying to help here but some sure have a negative response for someone needing help.
Yes both wires go on the + side of the coil, one is full battery power from the starter only when the key is in the start position. The other has power through a resister only in the run position, and buy the way the systems are not 12 volts, well only when the engine is not running it is 12 volts, when the engine runs it is 13.2 to about 14.5 usually if all is correctly operating. And yes you should use full power for your HEI if you want it to operate right and last a good long time regardless what others say they do or have tried. Anyone with a good understanding of eletrical power will tell you what damage low voltage can do to products. If you want to check all this out look at the wiring diagrams that others have listed on this site for free and then check out what your alternator is putting out and then decide what to do. Some have said good things to help some not so good. Good Luck in your fix.
Yes both wires go on the + side of the coil, one is full battery power from the starter only when the key is in the start position. The other has power through a resister only in the run position, and buy the way the systems are not 12 volts, well only when the engine is not running it is 12 volts, when the engine runs it is 13.2 to about 14.5 usually if all is correctly operating. And yes you should use full power for your HEI if you want it to operate right and last a good long time regardless what others say they do or have tried. Anyone with a good understanding of eletrical power will tell you what damage low voltage can do to products. If you want to check all this out look at the wiring diagrams that others have listed on this site for free and then check out what your alternator is putting out and then decide what to do. Some have said good things to help some not so good. Good Luck in your fix.
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Go to you local auto parts store and tell them you want a 13.2 - 14.5 volt battery for your car and see what they say.
Burning Brakes
Joined: Jan 2007
Posts: 1,057
Likes: 4
From: Concord Calif
Well maybe a bit but the point was to show what some had said that 9 volts was ok and does anyone really think that 5.5 to 6 volts drop to the HEI is OK? On and by the way a battery is really 12.6 at full charge
Melting Slicks
Joined: Nov 2003
Posts: 2,668
Likes: 119
From: St. Charles Mo
CI 5 & 8 Veteran
Listen to Manuel he knows of what he says. Just pullin you chain 
My advice is dump the points and go with electronic ignition. Using points these days is like trying to use a slide rule. I have one but have long forgot how to use it.
Bullshark
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Burning Brakes
Joined: Jan 2007
Posts: 1,057
Likes: 4
From: Concord Calif
So by your learning you can buy a "13.2" volt battery!!! I think you may have failed that class
Anyway all points have been covered here and I think that "Billysvette" wil be able to decide the right thing to do here. 
I'm done.
Tech Contributor
Joined: Jun 2004
Posts: 20,910
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Don't believe everything you read. You've been a member of this forum for enough years to have seen that some things in print are sheer BS. Quite often an old wive's tale gets circulated long enough to be accepted as fact. This is one of those.
Tech Contributor
Joined: Jun 2004
Posts: 20,910
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
I don't know if you are referring to my earlier comment (as I didn't mention a voltage drop in connection with HEI), but an HEI is designed to operate safely from 6-16 volts (and even 24 volts during winter time). During long cold cranking, the battery voltage will drop significantly (down to 6-8 volts), and it is not good for customer relations if the ignition system dropped out below 10-11 volts. There will generally be ample coil energy (for ignition) in the system even when the battery voltage drops to 6 volts.
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
I'm always up to learn something new. Anytime I can get a fact about something I do not know much about, electrical especially I'm always up for learning more about it.