[Narti]

There has been a lot of discussion on converting over to HEI and the removal of the original cloth covered "resistor" wire. Well here's some more to talk about. I was going to remove this wire on my 70 SS 396 and run a new one that would supply a full 12 volt's to my ignition. Just for S***'s& Giggle's I took out my multimeter and measured the voltage on the old resistor wire,guess what? 12 volt's! what's up with that?

 

[Carl Brune]

How did you measure it? You need the ignition circuit to be closed. This is the case if the points are closed, or (simpler) if you use a jumper wire to connnect the - terminal to ground. Then turn on the ignition and measure the voltage at the + terminal. Then remember to turn the ignition off. The voltage at the + terminal depends on the resistance in the resistor wire (balast) and that built into the coil. Hope this helps. --- Carl

 

[JWagner]

What you have is a case of "Ohm's Law" . The amount of voltage loss in a resistor is proportional to the current in the circuit. Your volt meter has negligible load on the resistor wire. The normal coil would have loaded the circuit to about 10 volts. Your HEI will have a greater current load than the regular coil. Find an alternate circuit to provide power from the fuse block or use a relay to do the job.

 

[Patrick Schamun]

HEI needs full 12 volts. Don't remove the orig. rest. wire. Tape it off. Run a 12 volt wire from your fuse box which is controled by the ign. switch. Make sure you don't pick up the acces. side of the ign. switch, or your ign. will be hot while the radio is on and your trying to your lady why you ran out of gas. Sometimes that takes a while.

 

[73Malibu]

I was able to remove the resistor wire spade from the firewall connector bundle (The part with all of the wires from the motor which bolts to the back of the fusebox) and replace it with a heavy gauge wire from a stock HEI car (76 Malibu). My car is a 73 so the connectors were the same type. I don't know if the older cars have the same connector spades or not. The spades are pushed into the plastic frame and sealed with evil black tar goop. The flat brass spades mate with the back of the fusebox and slide into place when you bolt it together.
Other wise tap into the IGN slot on the front of the Box, and also remove the "R" wire from the starter to the coil. This will melt your wires if you keep it trust me

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[Mike Sadoian]

73Malibu, thats what I did on my 69.I removed mine from a later model and it fit right in.It is the cleanest way to do it.

 

[pop]

I did it on my 66 the same way and it worked great. I suppose it deppens on the condition of your wiring

 

[TH]

You've all piqued my interest. We've got a '67 that we yanked the 283 from and we're putting in a 350 with HEI. I'm having trouble visualizing what you're talking about. I'm gonna have a look at things tonight and see what it is I have to do.

 

[ehjorten]

I did this on my '69 Chevelle. What he is talking about looks like a regular solderless spade connector but without the plastic cover. One side is cut to act like a one-way retaining tang. You can purchase a small bubble-pack of these at your local N.A.P.A. store for about 99 cents. You simply remove your firewall plug, locate the resistor wire, disengage the locking tang from using a small jewelers screwdriver or small diameter rod and pull out the connector and wire. Make-up a new (non-resistor wire) with a new connector, apply a little black silicone to the plug hole and push the connector in. It will lock itself in place and you will have 12 volts to your HEI and a very clean layout.

 

[Narti]

Hey guy's, I still don't think anyone has really answered my question why there's 12 volt's at this resistor when I measure it with my volt meter. A couple of you said something about how I measured it and something about Ohm's law. Well, I measured the voltage with the key "on" and if this was a resistance wire wouldn't it drop the voltage down no matter what was going through it? Point is, if there's reistance in the wire, why isn't it causing a voltage drop?

 

[TH]

And to that I add: Why the hell is there a resistor wire on there anyway? What is its purpose?

BTW, I've encountered the evil black tar goop and I'm moving in for the kill.

 

[Bob M]

[This message has been edited by Bob M (edited 07-12-99).]

 

[JWagner]

The purpose of the resistor wire is to allow the ignition to function well in both the cranking and running situations. The ignition system is designed to work on about 10 volts. So, when you are running, the resistor wire drops the 13+ volts to about 10 volts.When you are cranking, the system voltage drops to about 10 volts; this is when the resistor wire is bypassed and all available voltage (about 10) is applied to the coil. This permits a good spark in all modes of operation.

 

[73Malibu]

Some cars also would use a ballast resistor instead of resistor wire. Mine was labeled on the wire "resistance wire do not cut or splice" This means that the entire wire from the spade to the coil is of a certian resistance. You could measure the ohms with a meter, this should be higher than typical wire.

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[RAA]

If you have a resister wire you should be able to "measure" what that resistance is with an ohm meter. Don't measure the voltage (volts), measure the resistance (ohms)! If there is a very small resistance then you do not have a resister wire; if it is large you do.

 

[Mike Sadoian]

I have a classroom manual for electrical systems. It says the ballast resistor compensates for changes in voltage and current flow caused by engine speed and temperature changes. The resistor provides about one-half of the total primary circuit resistance and is the only part of the primary circut that is temperature compensated. The coil provides the other half of primary circuit resistance. At low speeds current flows through the circut for relitively long periods of time. The current flow heats the resistor, and its resistance increases. This drops the applied voltage at the coil. At higher speeds the points open more often and current flows for shorter periods of time. The ballast resistor cools, and its resistance drops. Higher voltage is applied to the coil, but the shorter current flow duration results in about the same magnetic suturation of the coil. The ballast resistor simply evens out the voltage and current flow of the primary circut. In doing so, it reduces peak voltage at the coil and thus reduces current flow that would burn the breaker points faster. This is the most noticeable effect. Although late-model domestic cars use electronic ignition with no points, a ballast resistor is somtimes used. to stabilize primary voltage and current flow. G.M. HEI does not use a resistor.

 

[FIG]

Just FYI for those that want to change out the old ballast wire, a new wire that has the corect ends on it is available from Year One. This includes a nice pink wire with a spade for the fuse box on one end and the other end has the correct plastic clip on it so that it connects into the HEI securely and cleanly.

FIG

 

[Patrick Schamun]

You people are making the answer to Narti question a total mess.
The answer is: HEI has to have full 12 volts.
If your reading 12 volts at the wire that goes to the pos. side of the coil, you should be ok...If this wire is the orignal resistor and it's reading 12 volt it probably has been shortened (sp). This wire can't be solered, beacuse it's stainless steel. It's better to replace it like other posts have said.....