Replacing Coil

[sharkdog]

Hi everybody,

My truck(1970 f-100 lwb 2wd 360 c6) wouldn't start the other day and I check and have no spark and assume it's probably my coil as it looks original to the truck and although my cap and rotor and wires are like 6-7 years old they probolly have less then a 1000k on them and still look in great condition. anyway I bought a coil at the parts store but haven't had the chance to test it yet cause I keep the truck at a friends place(generally go up there on the weekends). The one I got looks a little different then the one I took out. It's taller and the terminals are father apart and the old ones are labelled dist and bat and the new one is just + and - not to mention the label on it saying something about a resistor(see pic) anyway is this the wrong coil or just a newer design(the parts lady said this is the one her system tells her should fit). Thanks

[basketcase0302]

"sharkdog"Hi everybody,

My truck(1970 f-100 lwb 2wd 360 c6) wouldn't start the other day and I check and have no spark and assume it's probably my coil as it looks original to the truck and although my cap and rotor and wires are like 6-7 years old they probolly have less then a 1000k on them and still look in great condition. anyway I bought a coil at the parts store but haven't had the chance to test it yet cause I keep the truck at a friends place(generally go up there on the weekends). The one I got looks a little different then the one I took out. It's taller and the terminals are father apart and the old ones are labelled dist and bat and the new one is just + and - not to mention the label on it saying something about a resistor(see pic) anyway is this the wrong coil or just a newer design(the parts lady said this is the one her system tells her should fit). Thanks

We really need to know what ignition is in the truck, (does it have points in the distributor still-or has it been upgraded to some type of electronic type ignition)?

The points ignition uses the factory resistance wire built into the OEM factory wiring in the truck.
But...it is very possible that someone has changed the ignition to a Petronix / Duraspark or even HEI ignition which will need the full 12 volts, (not requiring a resister in line between the ignition switch and the coil "+" terminal. Not to be very concerned with the size being taller as the OEM coils were oil filled and of different design.

[390FE1972]

The picture of the new coil you bought looks like the Dennis Carpenter coil replacement seen here, they used to have a replacement coil that looked like the original "mustard" color top coil, but I don't see it anymore.

https://www.dennis-carpenter.com/en/tru ... t-replacem

Regards

[sharkdog]

Hi, Thanks for the response i'm positive nothing has been upgraded to electronic. i'm the fourth owner and the truck was in a friends family since 1971 so defiantly the original points type distributor. thanks again for the help and advice

[basketcase0302]

"sharkdog"Hi, Thanks for the response i'm positive nothing has been upgraded to electronic. i'm the fourth owner and the truck was in a friends family since 1971 so defiantly the original points type distributor. thanks again for the help and advice

Then you would disregard the writing on that one coil, (stating to use with an external resister) as your truck has the original resistance wiring in it. You can confirm the original resistance wiring hasn't been altered, (as a lot...of folks have done to thee trucks!) using a voltage meter while cranking measuring the voltage being sent to the coil.
Electronic or Petronix type ignition not needing a resister-requiring the full 12 volts VERSUS points type ignition that requires around 9 volts so the points last longer.