I just read the distributor questions thread from ol'blue150 and got some good info, but instead of hijacking his thread (and mine is a little different) I'll start this thread.

I have a 74 F250 4x4, with a previously swapped in 460, that I am converting my points ignition for a 75 electronic ignition. I purchased a dizzy, cap, rotor, coil and wires at Napa. I had an old control module and EI wiring harness laying around in my garage that tested OK so I'll use that for now.

A couple of questions please:

1) In my 74, the existing positive coil wire shows 7 volts at the coil when the ignition is in the run position (with engine off) While running it shows 12 volts. Does this mean that I currently have a ballast resistor wire in the wiring to that point? Should I install a ballast resistor just to make sure. I don't want to fry my new coil.

2) I Used a tester to identify which of the wires in the new Electronic Ignition (EI) wiring harness powers to the positive (+) coil connection. I think that all I have to do is wire the existing positive coil wire (from the 74 truck) into the wire in the new EI wiring harness. Does this sound correct? Is there anything else I might need to wire in, i.e. ballast resistor, other wires, grounds, etc.

BTW, I assume that the dizzy will be self grounding on the block. Is this correct?

Thanks in advance, Tim

 

Well, it looks like my progress is on hold. The parts guy at Napa sold me the wrong plug wires for the new EI distributor I installed. Guess I'll be heading back down to the big city to replace them. Wont be able to try it all out until tomorrow cause it will be dark by the time I get home. Oh well.

Hey, does anyone know how to answer my above questions? If I need to clarify them, please let me know. I'll check back tonight, when I get back from changing out those wires in town.

 

You might as well go with the '76 and up ignition and get the bigger cap, wires and blue grommet module if you're gonna upgrade from points.

 

Should be 12 volts at the coil in START and around 7 volts in RUN.

Josh

 

OK, new info. I cut the connector off at the end of that + coil wire to the points ignition and added the spade connector to attach to the new coil. Now it reads 12 volts with engine off and key in run position (must have been a bad connection at the old connector?).

Of course I can't run the engine yet as I am still hooking up the new EI dizzy, but before I pulled out the points distributor, the + coil connector showed 12 volts while the engine was running. So it seems to read the same while running or not. Should I assume that I don't have a resistor wire in line after the ignition switch???

 

Too late for that. The dizzy and cap are installed. Oh well, next time.

 

Bad move, you'll eventually upgrade.

 

I'll check into it at Napa. Maybe they'll let me swap before I fire it up. What's the difference between the two? It's possible that I already have the one you refer to. Can you describe the difference so I can check out mine to see which one I have. I'm not sure. I thought they were all the same through the eighties or so.

 

Duraspark I, one pc. small dizzy cap, 7mm wires. (male wires, female cap)

Duraspark II, two pc. big dizzy cap, 8mm wires. (female wires, male cap)

 

Needs to be around 7 volts while the engine is RUNNING (or key is in RUN) whether it is for points or Duraspark.

A constant 12 volts would burn out points in no time.

I would reckon a PO bypassed the resistor wire for some reason.

Josh

 

Cool!!! That's the one I have, Duraspark II. Its got the male connectors on the dizzy cap.

Hey, I'm having trouble starting the truck now, with the new stuff in place. I have 12 volts at the coil, 12 volts at the coil wire when the key is on. I had the wife turn over the engine with the coil wire disconnected but close to the dizzy connection and didn't get an arc. Am I missing something here in the wiring? Please see the #1 post on this thread. I still need help with this set up. More now than before as I'm unable to make things come together. Someone please help.

 

How do you know the module is actually good? Same goes for the pick-up in the distributor.

How did you wire in the wiring harness?

Josh

 

I had the module tested at Napa. I wired in the old coil wire into the harness where I cut the wires on the new junk yard harness, where the wiring came from the fire wall. Should the + wire go into the wiring at the Module instead of/or along with into the firewall harness? I think my problem is where I did (or didn't) wire in the positive.

Also, is there any other wires that need to be connected somewhere to power or ground?

 

OK, I'm going to head back to my house and try wiring the + coil wire into the control module two wire plug (red). Then, If I'm on the right track, I'll wire the white wire at the two wire control module plug to the "S" terminal on the silenoid. Does this sound correct?

 

1974 DuraSpark Ignition module is a ONE YEAR only module: D4AZ12A199C / Marked: D4AE-12A199-A1A, or -A1D, or -A2A, or A2C, or A2D.

1975 DuraSpark Ignition Module is a ONE YEAR only module: D5AZ12A199C / Marked: D5AE-12A199-A1A, or -A1B, or A1D, or -A2A, or A2B, or -A2C, or A2D..

1976, Ford came out with the BLUE module, so called because above where the wires out, there's a blue plastic square.

This same blue module was used into the 1990's > >

1U2Z12A199AA (Motorcraft DY893) / 1U2Z12A199A replaced D9VZ12A199A & D6AZ12A199A.

1976/79: Some cars/trucks sold new in CA used a RED module. Do not use it...it's a total POS!

The same magnetic stator aka pickup coil was used in all 1974/79 V8 cars/trucks (except 1979 LTD's with EEC). > >

D4PZ12A112A (Motorcraft DU1A).

Autoparts store bought DuraSpark modules: Most are made in China and are CRAP!

They oughtta call 'em the miracle modules, cuz if they last a year, it's a miracle!