Duraspark 2 ignition wiring question

[gws34]

I am trying to change my 75 bronco that had a points distributor in it over to a duraspark 2.

The bronco has a centech wiring harness that has been in there for many years.

I purchased a painless wiring duraspark 2 harness. The distributor and ignition module that I purchased are for a 1977 bronco (Duraspark 2)

Reading in the centech wiring harness manual that i printed from on line and then the manual that came with the duraspark harness, I am confused what goes to the Resistor ballast and what does not.

According to the Duraspark manual
The resistor gets the red wire from the ignition module and the white wire goes to the S side of the starter relay. and the red/brown wire from the coil goes to the other side of the resistor.

The centech setup has a blue, violet, and White wire.....

Blue wire goes to one side of ballast. But is that the side with the Red wire from the control module or the red/brown with the coil?

The violet wire, according to centech goes to the white wire from the control module, but the Duraspark amnual says the white goes to the starter solenoid.

And the white wire from the centech harness labeled Coil plus goes to the resistor and then to coil positive. The duraspark kit has the red brown wire going from the resistor to the coil positive.

Does this mean the red/brown wire (from the Duraspark wiring that connects to coil positive) and the White coil positive wire connect to the one side of the resistor. and the Blue from centech (labeledignition power from Centech) and the red from the ignition module go to the other side of the resistor ballast? And the purple (centech start wire) and white wire from the contol module go to the S terminal on the starter solenoid?

Just want to make sure I got this right before I try to start it and fry everything if it is wrong.

Thanks
Glen

 

[savage]

I have a centech wiring harness on my 74 and wired the duraspark 2 into the centech harness, its been a while since I did it ,but here are the threads I have hope it helps. https://classicbroncos.com/forums/showthread.php?t=258904 and https://classicbroncos.com/forums/showthread.php?t=258757

 

[DirtDonk]

I purchased a painless wiring duraspark 2 harness. The distributor and ignition module that I purchased are for a 1977 bronco (Duraspark 2)

Parts are compatible. The Painless harness is set up for a "blue grommet" module, so even though yours should be, double check the color.
The distributors all used the same electronics and 3-wire connector, so you're good there too.

Reading in the centech wiring harness manual that i printed from on line and then the manual that came with the duraspark harness, I am confused what goes to the Resistor ballast and what does not.

Do you currently have the ballast resistor installed to run your points ignition? I assume so, but wanted to verify.

According to the Duraspark manual

Which Dura Spark manual? Or did you mean Centech?

The resistor gets the red wire from the ignition module and the white wire goes to the S side of the starter relay. and the red/brown wire from the coil goes to the other side of the resistor.

As far as I know, there are no applications where a blue-grommet module uses the resistor to power the module. For those ONLY the coil uses the resistor.
Just like it did with the points then, you will continue to use it with the new setup.

The centech setup has a blue, violet, and White wire....

Blue is power to the coil, but there was a second Blue wire in the original Centech harness that was for powering up the module I thought. Maybe I'm wrong, but if you installed the harness yourself, do you remember cutting off any wires? Or maybe burying them in the harness for later use?
White wire is from the "S" terminal of the starter relay.
Purple wire is to the "I" side, BUT it is also a START signal that can be used for the White wire on the module.

Blue wire goes to one side of ballast. But is that the side with the Red wire from the control module or the red/brown with the coil?

Blue wire is 12v and goes to what we'll call the "input" side of the ballast. The coil power wire runs from the "output" side of the ballast to the coil.
Red wire from the module goes to the same "input" side as the Blue wire.
The Centech White wire from the starter relay goes to the "output" side of the ballast to give the coil some extra current and maybe voltage during START only.
This White wire is NOT connected to the White wire in the 2-wire module connector.

The violet wire, according to centech goes to the white wire from the control module, but the Duraspark manual says the white goes to the starter solenoid.

Because Painless does not write their instructions for a Centech harness. They write it for a stock harness.
And in your case, Purple IS from the same START signal as the starter relay's "S" terminal.
The original factory Dura Spark connection to the White module wire came directly from the ignition switch and the Red w/blue wire that also went to the starter relay. In your case, your switch only goes to the starter relay so you're tapping into it to get a START signal to the module. However, if you leave that White wire blank the engine will still run. Either the Red OR the White wire can power up the module, so you don't actually need both to get it to run. But you need both to hook it up like Ford intended.

And the white wire from the centech harness labeled Coil plus goes to the resistor and then to coil positive. The duraspark kit has the red brown wire going from the resistor to the coil positive.

Are you sure it's Red w/brown? Could it be a discolored Red w/green?
The White wire is correct. Just make sure it goes to the resistor's output side, and not the input side or it does not do it's job.
Look over at the starter relay and make sure that you have the other end of the White wire on the "I" terminal. If so you're good to go there.
The Painless is correct too, with the Green w/brown/red wire going from the output side of the resistor over to the coil.

Does this mean the red/brown wire (from the Duraspark wiring that connects to coil positive) and the White coil positive wire connect to the one side of the resistor.

Yes. The "output" side.

...and the Blue from centech (labeled ignition power from Centech) and the red from the ignition module go to the other side of the resistor ballast?

Yes. They share the "input" side so they get the full 12v.

And the purple (centech start wire) and white wire from the control module go to the S terminal on the starter solenoid?

Yes.

Just want to make sure I got this right before I try to start it and fry everything if it is wrong.

What could go wrong?%)
It's only your time, money and new parts after all. Right?;D

Good luck.

Paul

 

[jckkys]

Who put a points distributor in a '75? It should have a breakerless distributor just like the DurasparkII. The original '75 harness has a resistance wire built in too. It may work well with no additional ballast. Here is a good article that has wire colors and routing;https://pantera.infopop.cc/topic/duraspark-vs-msd-distributor It also has the ignition system part numbers and electrical values so you can select components that are compatible.

 

[Viperwolf1]

Ignore wire colors. Match the wire routing by the pins on the connectors and you'll be set without wire color conversion charts which may or may not be correct.

 

[gws34]

Thank you Viperwolf and everyone. I had found your diagrams before viperwolf and that was helpful.

I did get it started today.

Basically the big question was what wires from the Centech Harness lined up with what on the resistor. So it was really a Centech to Painless wiring question.

What seemed to work for me is on the input side of the resistor is the Centech's Blue wire labeled ignition power and the Red wire from the Painless harness labeled Input side of Resistor. and then the other side (output) has the White wire from Centech harness labeled Coil Positive and the Red w/ brown stripe from the Painless harness labeled that it goes to output side of Resistor.

Also purple from Centech harness and white from Painless go to S terminal on relay and white from centech harness and brown from Painless harness go to "I" terminal on relay.

I did spend the money and by the pre made Duraspark 2 harness from painless instead of building it as Viperwolf has mentioned in other posts.

Yes the previous Owner did many things to this bronco that I have just been finding as I work through it. The latest today was it was the wrong coil to fit the painless harness so I had to run back out to the autoparts store just to finish this part of the project.

Hopefully getting it inspected for emissions and getting it on the road in the next few weeks.

Thank you everyone.

 

[gws34]

Thank you Paul for all of your help also!

 

[clintonvillian]

Is there one module that is better than the others. I've seen a lot of reference to the blue insulator.

That is only on 76-77 applications, correct?

I too will be running a painless harness.

 

[DirtDonk]

Is there one module that is better than the others. I've seen a lot of reference to the blue insulator.

Better is relative, but yes the blue insulator (or "strain relief" or "Blue Grommet") modules are usually your best choice due to availability, price and they are a direct fit to the aftermarket Dura Spark harnesses.
But you still need to source a good brand because like so many other things these days, buying cheap is a crap shoot and you may be stranded on the side of the road one day.
Often just out of your driveway!

That is only on 76-77 applications, correct?

If you're talking Broncos only, then yes I think that is correct. Otherwise they went all the way through '79 for the full-size trucks.

I too will be running a painless harness.

If the Painless main Bronco harness, the main harness does not really care what type of ignition you use. It's versatile and can be made to work with pretty much anything.
If you're talking about the Painless ignition harness for Dura Spark, then yes it's set up for the Blue module wiring.
There may have been other color modules that had the same wiring order in the connectors, but I don't know which ones those might have been and it's probably not worth trying to source the oddball ones anyway.

Paul

 

[reamer]

Why not go with Pertroincs and remove the points?

 

[Teal68]

I convert all my old stuff to Duraspark rather than aftermarket. Even 69 Cleveland powered Mustang.

I always use a coil that requires no resistor. One less thing needed to go bad or clutter the engine bay is the way I see it.

 

[clintonvillian]

I convert all my old stuff to Duraspark rather than aftermarket. Even 69 Cleveland powered Mustang.

I always use a coil that requires no resistor. One less thing needed to go bad or clutter the engine bay is the way I see it.

Do you have any part numbers for the coils you have found...it seems like everyone I find requires a resistor...

 

[Teal68]

Do you have any part numbers for the coils you have found...it seems like everyone I find requires a resistor...

EDIT: I also like to use Pertronix coils too when looking for a bit more voltage.
Keep in mind if you are using the factory harness your coil + lead may already have resistance built into it. If you only test that lead with the key on it will be mis-leading and read 12 volts. To test it properly you have to have electricity flowing thru it. Meaning, the vehicle has to be running or something has to be hooked to it that is actually consuming electricity like a light bulb or electric motor.

Here you go for a parts store option:

 

[gr8scott]

Here's another:

https://www.jegs.com/i/JEGS/555/40117/10002/-1


And another:

https://www.amazon.com/Standard-Motor-Products-UC15T-Ignition/dp/B00809W952/