# 65 GTO resistance wire



## olde-goat (Feb 1, 2009)

Before I replace the main harness into my 65 GTO resto, thought I would double check wire continuity and resistance. All wires check out fine with exception of one. Brown wire starts off in the fuse block makes a T connection; one goes to ignition switch, another to the gas gauge ( good continuity and 0 resistance) and third is connected to brown/ white wire which ends up in the bulk head connector which when connected to the engine side of the connector changes to a brown wire and goes to the regulator. The brown/white segment measures almost 10 ohms. All these follow the wiring schematic exactly. The brown/white is referred to as a resistance wire in the schematic. Not sure what this means, should this wire read 10 ohms?


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## chin (Jan 5, 2011)

Sounds like the resistance wire could be used to drop current going through the bulk head to components. Does the wire appear to be rock hard and pre-formed like it has been there for 46 years? That might be an indicator that it's original.


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## dimitri (Feb 13, 2009)

When your engine is running your alt is putting out about 13.7 volts. This will fry the points!!! You should read about 9 to 9.6 max at the end of that resister wire. 

If you swap out to HEI do not use this for a power souce. HEI must have full voltage.


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## Rukee (Feb 8, 2007)

Yeah, I'm thinking also that wire should go to the coil, not the voltage regulator.
Isn't the resistance part of the wire on the coil (+)wire??
Did you see the car run with it connected to the VR?


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## 05GTO (Oct 6, 2004)

dimitri said:


> When your engine is running your alt is putting out about 13.7 volts. This will fry the points!!! You should read about 9 to 9.6 max at the end of that resister wire.
> 
> If you swap out to HEI do not use this for a power souce. HEI must have full voltage.


:agree



Rukee said:


> Yeah, I'm thinking also that wire should go to the coil, not the voltage regulator.
> Isn't the resistance part of the wire on the coil (+)wire??
> Did you see the car run with it connected to the VR?


:agree


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## olde-goat (Feb 1, 2009)

According to the schematic there are two 'resistance wires'. The one that Rukee refers to and the one located on the passengers side of the firewall. From the information that I am starting to get is that the 'resistance wire' cuts down the voltage that goes to the points in the regulator. I assume that this is necessary to avoid burning up the regulator points. This wire is in excellent condition with no signs of overheating. Unfortunately this car came in boxes and I did not have the opportunity to see it in use. 

On another note I cleaned the terminals, plugs connectors etc of my original harness. All wires prove out to be in excellent condition, very pliable, no signs of heat damage, or cracking. Sure is a good way to learn about the wiring. Once you go through the harness a few times you get an appreciation of how relatively simple it is.


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## JustAl (Mar 20, 2010)

The resistance wire was indeed used to reduce voltage to the coil primary circuit for normal running. Other makers used an external ballast resistor for the same purpose. It was bypassed during cranking with a wire that was fed from a terminal located on the starter solenoid. This gave full power during the starter operation which already dropped the voltage due to it's heavy current draw. Whether of not you will need it depends on the type of ignition system you will be using.


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