Cool thread, turned out to be an open "resistance wire"...
Maybe just the connections tho? {shrug}

After you get it going I would like to know what really went wrong with that sucker.
Is it burned in two?

Anyway...
Had similar symptoms when my '75's ignition module went out in '79. :)
But mine was intermittent, so not exactly the same.
Let off the key and it'd died or sputter along or run fine. LOL :)

Me and Dennis got a guy going one night here, he had the early DuraSpark system
and was having the same symptoms, his was the module.

Alvin in AZ

 

The Resistance wire is rated between 1.05 to 1.40 OHMS. I think they are still avaliable at Ford. They are year specific so make sure you mention the year.


Did you check both sides of the resistance wire on the truck, at both splices, like I posted earlier? You didn't say. This is to confirm if it's the resistor wire, or a break in a connection or wire like Alvin suggested.

 

Yep, if he had power at the Red/green coil wire, the next test would have been the module.

Since no power at the coil's Red/Green wire, it took us in a different direction.

 

what exactly is the resistance wire for? everyone else i have talked to said, just run a straight wire to the coil...

 

Cool question, I'll start it off...

If the coil was made to take 12 volts all the time, it wouldn't work out so
good when the battery voltage is being drawn down while the starter is
engaged.

So they came up with the idea to make the coil work at a lower voltage
most of the time through the resistance wire and bypass that resistance
while you have the key in the start position. :)

Alvin in AZ

 

Also to add to this, The stock Coil Will get hot and burn up with a full 12 volts on it all the time.

The stock coil is only meant to run around 7 or 8 volts, if I remember right. It is 2AM

This is why the resistance wire is in circut.

 

ok i have a question that is relevant to this thread. After having read everything here, I'm a bit confused and i don't want to burn up my coil, so I'd better ask now. I just dropped a 351M into my 74 F 100. The 302 i pulled out didn't have electronic ignition, the 351 does. i have everything wired up, but had to improvise a bit. i did buy a resistor wire, but was unsure until now, where to install it. My quesiton is this... Would there be a factory resistor wire splice in my truck since it didn't already have electronic ignition? And if there's not, how and where do i install it? Any help is greatly appreciated.

 

well i dont have the stock coil.. i had to change it since it was toast anyways... so i have an accel superstock coil? i'm not sure of the specs on it... but i would imagine i could just hook up a wire to it?

 

There definitely -was- one. ;)
It's about the coil and the starter's load, not the system hooked to it.
...like "81" talked about.

---------------------------

81, mine reads about 10 volts while it's running and I'm wondering what
others are getting.

----------------------------

93PGT, "git chur meter out! ;)" and you tell us what you've got. :)

The resistance wire effectively halves the current going through the coil.
Since your other coil "was toast" makes me wonder if no resistor wire
wasn't what "toasted;)" it?

The coil is made to run continuously on the lower current/voltage.
Just so it would be easy to bypass the current limiter while starting.
What little bit of over lap during switching (if any) won't hurt it that
quickly so won't hurt it but over time (the theory is) it will burn it up.

Alvin in AZ

 

i had the same issues with my truck, key the ignition it would start then when in run it would die. so i just put a wire from the bat straight to the coil+ and its been fine ever since. i did that about 2 months ago and have no issues with it. this truck is a daily driver, i go to collage 3 days a week

 

Is that why they call 'em...
"edjikated idiots" ?? :)

When the coil goes out, you are going to be stuck right there until you
replace the coil. That's when a stupid-ugly-old-Gringo stops and sez...
"hey, what's going on? :)"

Did that today, in front of Ace Hardware, but it was a Chicano and he had
everything under control already. :) "23 cents to fix it, hate to ask what
GM would charge for the this part ;)" He had a broken hard plastic tube he
slipped a hunk of vinyl hose over it, I handed him my pocket knife -open-
he cut the vinyl tube and for 23 cents... he can fix it two more times! LOL :)

Alvin in AZ
ps-
Chicano = born in the USA
Messcan = born in Mexico
Injun = >not< born in India LOL :)
Gringo = pale faced person -looks like a grub- as if they just crawled out
from under a rock or out of the ground or something, the way Alvin looks.
pps- the pocket knife...
http://www.panix.com/~alvinj/ggrampa.htm

 

93PGT: Some Aftermarket Coils are made to Run on 12 Volts.

Not Sure if The coil You Mention 93PGT is meant to use 12 volts or not, it's usually written on the coil.


I Just Know the Stock ones are not meant to. 10 Volts also sounds Right Alvin.

I wonder if it was the non stock coil that fried the Resistance Wire?

I Guess you could try running just a straight wire to your coil 93PGT, but if it starts burning coils, then you know...

 

So you have 12 Volts hooked to Your Coil all the time.

Not A Very Good Idea IMO.

 

Hmmm... if it was a "hotter" coil to start with... when the coil's spark was
reduced by the battery drawing down the voltage it'd still be like a "regular"
coil's output. So it'd still start ok but still not up to what a "hot" 10 volt coil
could do, since the 10 volt coil with a bypass resistor do both jobs better.

Sounds like a silly idea to me. YMMV

Alvin in AZ

 

yea well my truck is in bad shape ,i have 1 bolt holding the cab on, and the front cab mounts are gone. so i bought my bros truck and im putting his body on my frame. but im keeping my wire harness and the other interier guts. when i my body lift and start tearing mine all down i will replace any worn or damaged wires, thinking about getting a new harness from painless

im uploading some pics to photobucket, will have it up in a minute