Coil question related to Pertronix installation

[Bmachine]

As I was reading the installation instructions for my Pertronix 1867 into my carbed cs, I noticed they recommended hooking the red wire to the positive of the coil with the resistor in between. Now my car is a 74 and therefore does not have a ballast resistor but a wire resistor instead. Only problem is, I can't find where that wire is... I have what appears to be a black original coil although the part number on the bottom is a bit odd. It is 0221 119 C17. But that C is backwards. See photo. I would think it is supposed to be a 0 and the stamp did not print it clearly but it really looks like it is a backwards C and not a 0.

So what coil would this be? Is it the original black one?

If so, I believe it is supposed to use a resistor. However the Pertronix instructions say that the coil needs to have minimum of 1.5 ohm resistance. When I measure it, it gives me about 2.0 ohms across the + and - without any wires attached. Does that mean that I can safely attach the red wire from the Pertronix directly to the positive of the coil, regardless of where the resistor wire is?

Thank you

 

[HB Chris]

From the 2002faq:

It can be confusing because people refer to the coils by their historical colors.

The newly produced Bosch coils can appear quite different in color depending upon when it was produced.

The 00013 "red" coil I think is silver with red sticker now.
The 00010 "black" coil is silver with green sticker now. (Can be found in black)
The 00012 "blue" coil is silver with blue sticker now.

The 00013 needs a 1.8 ohm external resistor (either ceramic or wire).
The 00010 needs a 0.9 ohm external resistor (either ceramic or wire).
The 00012 has enough internal resistance and doesn't need an external resistor.

 

[Bmachine]

Thanks for the info Chris.

But I don't think mine is a "newly produced" one. It is looking fairly old. It also does not have any number resembling 000xx on it.

Bo

 

[Stevehose]

That's not a backward C, it's a 0 not embossed enough. So you have Bosch 0221 119 017 which is an old Black coil. Therefore for '74 you should have a resistor wire somewhere unless removed somewhere along the way. I don't know what they look like but it would probably be coming from the ignition switch circuit to the coil. Maybe a clear-ish insulated wire. Perhaps google Pertronix and resistor wire install and see what comes up.

 

[lloyd]

That's not a backward C, it's a 0 not embossed enough. So you have Bosch 0221 119 017 which is an old Black coil. Therefore for '74 you should have a resistor wire somewhere unless removed somewhere along the way. I don't know what they look like but it would probably be coming from the ignition switch circuit to the coil. Maybe a clear-ish insulated wire. Perhaps google Pertronix and resistor wire install and see what comes up.

This may give you an idea of how the typical coil resistor wire looks. It is the thick "yellowed" (originally clear) wire that is spliced to the green wire (below). My limited experience with those wires, as used in both E9 and E10 models, is that they have been replaced or are in need of replacement. The last one I encountered (a long time ago) went from yellow to tan to brown and clearly exhibited signs of overheating (brittle). As the function of this wire is to "resist" it continues to perform its job at the risk of completely shutting off the tap when things get hot enough.

This is one of those instances where the old style ceramic ballast resistor is likely more durable than its replacement. Conversely, the resistor wire is probably a weight saver.

 

[Bmachine]

Thanks very much Lloyd and Steve.

I measured the voltage on the coil and it was giving me 7.3 volts. The Pertornix instructions require between 6 and 9 so I figure it was safe to hook it up.

I did and it works great!.

I still want to find where this wire is though bc it doesn't make sense that I get 2 ohms across the coil and 7.2 volts with a non resistor coil...