I am putting together a temporary wiring harness fire up my 351W in my '50 F-1. I am using a Duraspark II ignition with the factory coil and box. Do I need some type of resistor between the coil and the ignition switch?

 

No. The Dura Spark system uses full voltage to the coil.
Resistors are used with points type ignition to to make life easier for the points.

 

Ditto.

And thanks for keeping a Ford in your Ford!

 

No problem. The last thing I wanted was a Chevord

 

I have to disagree, the Dura-Spark uses a resistor wire from the ignition to the red wire on the box and gets a full 12V from the I terminal on the starter relay to the white wire.

 

Okay, to the next level. I have diagram I pulled off the net showing the green wire from the coil going to the green wire (four connector plug) to the ignition module. The red wire from the coil going thru a 1.3 ohm resistor to the red wire on the two connector plug to the ignition module. The red wire also shows termination on the ignition switch. The white wire this same connector at the ignition module also goes to the ignition switch. Boy am I confused. Where to I get this resistor and how do I wire it in? And of course there is always the starter solinoid.

 

Ah my favorite ignition system...... yes it needs a resistor for normal running, I heard it is to stop the coil from overheating. I use a Chrysler ballast resistor vice the Ford resistor wire....... any parts store should be able to supply one they will know when you ask for it which one it is..... I think it from an early 80's maybe 70's Mopar.
I have attached a basic Duraspark diagram.

DurasparkII Conversion

 

My bad on the info.
I was thinking about power to the module instead of the coil. The module uses two 12V circuits. One that is hot in the run position and the other that is hot when cranking. The coil does have a resistor in the run circuit that is bypassed when cranking.
I found a wiring diagram also and scanned it but haven't been able to get it or a link on here. I see you have found one as well as Sparky posting a link.
At least you are on the right track. Sorry for getting you headed the wrong direction.

Richard

 

*scratches head and wonders...did I put a resistor on my truck? I'm gonna have to check on that 'cause I've been runnin my system for years* Hmm...

 

Thanks all. Sparky, the link was great and if you all hear a loud boom, you know I did it wrong.

 

I'll chim in on this I replaced my points 9 years ago with the duraspart system I used the same diaghram listed in the link above, haven't had any problems so far.

 

I put a new solenoid (among other things) on my 351w a year and a half ago. The truck would get up to operating temp and would stumble, die, and be very hard to re-light. Had the same trouble back in the 80's with some other Ford PU's, and was always the "brain box". Change it...good to go. I did that with my 55 (changed the module) no help. new coil. ditto. Bought a rebuilt duraII dizzy. no help. Dissaembled the Edelbrock 1406, thinking maybe it was fuel. Nothing. I posted a similar question on here after exhausting everything I could think of. Several suggestions, no real help. I Googled "Duraspark Ignitions" and printed the resulting diagram. The problem? I had the white wire on one of the small posts on the solenoid on the wrong post. I think I was overheating the coil.

 

Being rather slow, a friend suggested checking the instructions that come with the new EZ Wiring harness I have not yet opened. Low and behold it covered everything I needed to know except the ballast resistor. I picked one up today and hope to get going early next week.