Function of the cold start coil

[Grumblebuns]

Digging through my spare parts shelves, I found a gear reduction starter for a twin cam motor that I bought many years ago. I'm thinking of installing in a TCS that I'm trying to get on the road. The starter for some reason does not have a terminal to the coil (cold start coil per the wiring diagram). Has anyone tried to start their car without this connection? 

Trying to revive dead memory cells here but I thought the connection from the starter solenoid to the coil was to apply full battery voltage to the distributor when switching the ignition to START. Once the motor is running, the key is released to RUN and the distributor gets 9v from the ballast resistor for normal running. If this is the case, can I use this starter for the TCS?

Joji Tokumoto
Fallbrook, CA

 

[LotusJoe]

Joji,
The cold start terminal on the starter was intended to bypass the resistor wire during the start phase. It supplies a full 12 volts to the coil but only during the time the starter is engaged. After that power to the coil is supplied via the resistor wire which drops the voltage so as not to burn the coil out. I would try it without the circuit. If the car is tuned well it shouldn't matter. If the car is hard to start I can sketch out a quick circuit using a relay that will work.

[Grumblebuns]

Thanks Joe. I'll install the starter and see how well the car starts in a few weeks. If I have issues, I'll let you know.

Joji

[Bainford]

Many of the aftermarket coils require the ballast resistor to be removed from the circuit. If you happen have one of these coils, the lack of a 'cold start' circuit may be moot. If you do not have such a coil, they are generally quite inexpensive, if that serves your purpose.

[Grumblebuns]

Looking further into the ignition circuit, it appears that the stock coil has been replaced. Can't tell what brand unless I remove it from its current position. From the picture, anyone know if what is shown is a ballast resistor on the right terminal? Without the original instructions, is there any way to determine if this coil requires a ballast resistor?



Joji Tokumoto
Fallbrook, Ca

[Arizona]

Judging by the color might that be a Lucas Gold Sport coil? If so they are for non ballast systems.

[4129R]

Is it possible to measure the voltage across from left to right for the terminal which looks like it has had the voltage reduced, with the ignition on?

If it is 12v, then it probably isn't a ballast resistor, and the new coil probably doesn't need it. If it is 9v, then the ballast resister is working, and the coil will normally run 9v unless starting.

[LotusJoe]

Many of the aftermarket coils require the ballast resistor to be removed from the circuit. If you happen have one of these coils, the lack of a 'cold start' circuit may be moot. If you do not have such a coil, they are generally quite inexpensive, if that serves your purpose.

[LotusJoe]

Looking further into the ignition circuit, it appears that the stock coil has been replaced. Can't tell what brand unless I remove it from its current position. From the picture, anyone know if what is shown is a ballast resistor on the right terminal? Without the original instructions, is there any way to determine if this coil requires a ballast resistor?

Joji Tokumoto
Fallbrook, Ca

Joji, Looking at the wiring diagram it looks as if the ballast resistor is or was mounted next to the coil. I only see the white wire coming from the number 3 pole on the ignition switch and going to the hot side of the coil. Your coil may have been changed to a non-ballast? ? If that is the case, there is no need for the hot start wire.

[EuropaTC]

Joji,

I can't tell from the photo what you've got, but I do have some notes which I quite unashamedly copied from another website for when I was first installing electronic ignitions, and I think they are relevant;

Ignition Coils:

If the coil does not have standard or ballast written on the front you will need to test with a multimeter.  Set meter to Ohms. test between + and -. A standard coil will read around 3 Ohms a Ballast coil will read around 1.5 Ohms.

To replace a Ballast coil with a standard coil is quite simple. If you have a visible resistor you just need to bypass and connect the live feed direct to the coil. If you have a ballast wire this may be more difficult to identify. This may be a wire from the ignition key to coil or may just be a part of the wire. Normally the ballast wire will have a unique colour in the loom to
make it easier to identify. If you are unsure just run a full wire from the Ignition key to the + side of the coil.               


Personally I would just install a standard 12v coil and do away with the ballast system. I know the theory is for better starting but a standard 12v works fine, especially if you move to electronic ignition and it's just one less component to fail !

Brian

[Grumblebuns]

Joji,

I can't tell from the photo what you've got, but I do have some notes which I quite unashamedly copied from another website for when I was first installing electronic ignitions, and I think they are relevant;

Ignition Coils:

If the coil does not have standard or ballast written on the front you will need to test with a multimeter.  Set meter to Ohms. test between + and -. A standard coil will read around 3 Ohms a Ballast coil will read around 1.5 Ohms.

To replace a Ballast coil with a standard coil is quite simple. If you have a visible resistor you just need to bypass and connect the live feed direct to the coil. If you have a ballast wire this may be more difficult to identify. This may be a wire from the ignition key to coil or may just be a part of the wire. Normally the ballast wire will have a unique colour in the loom to
make it easier to identify. If you are unsure just run a full wire from the Ignition key to the + side of the coil.               


Personally I would just install a standard 12v coil and do away with the ballast system. I know the theory is for better starting but a standard 12v works fine, especially if you move to electronic ignition and it's just one less component to fail !

Brian

Just finished checking the resistance across the coil primary terminals, I got 2.9 ohms. Looks like a non ballast coil.


The new starter motor is installed and the wire to the coil is tucked away. Won't be able to do the initial start for a couple more weeks but I appreciate all the help and input.

Joji Tokumoto
Fallbrook, Ca