Hello, so I just replaced my coil on a 1952 F1 truck, truck is converted to a 12v neg ground as far as i know. I needed a replacement coil and called up NAPA and they sold me this, the one on the left that say "Use With External Resistor" vs the old one that says "No External Resistor Required".

I installed the new NAPA and the truck fired right up, and has good power but I do not know if I have an External Resistor.

Will this new coil be fine to run or should I be looking for a resistor or new coil??

 

Yes, you need a ballast resistor, or your points will not last very long. NAPA coil IC14 is internally resisted and fits in the original clamp. You want a total of about 3 ohms in the coil primary and ballast. Some options for ballasts:
ICR23 ballast resistor is 1.2 ohms, ceramic body
https://www.napaonline.com/en/p/ECHICR23

ICR37 ballast resistor is 1.6 ohms, ceramic body, metal mounting bracket
https://www.napaonline.com/en/p/ECHICR37

 

Or just buy a coil that doesn't require an external resistor. That way you don't have to wire in the resistor, bypass the resistor while starting, and find a place to mount it.

 

Thanks for the responses, if I had a ballast resistor would it be in plain view or hidden somewhere?

 

Trace the wire from the ignition switch. But with your old coil, it didn't need one, so I wouldn't expect there is one.

 

They usually are mounted on the firewall but can be mounted in other places. I suspect you don't have one since your original coil did not require it. If you are using a ballast resister, you must have the wiring to support it including a starter solenoid that has the connection to bypass the resistor when starting. Here is a picture of a ballast mount on the firewall (white ceramic device). Note the starter solenoid has four terminals (one on each side and two in front) with the right hand front terminal being the bypass circuit.

 

Thanks for all the help, I am going to give NAPA a call tomorrow morning and see if they will exhange/return the current one I have. Not sure if NAPA returns electrical products.

So I just need to get the IC14 coil and that will be plug and play good to go? Thanks all!

 

That should work . . .

 

Right on, will update tomorrow and share some pics of the truck! Appreciate it.

 

Thanks for the help all exchanged the coil for a IC14 and works like a charm. Appreciate it.