77Â’ Bronco factory ignition wiring help

[IllpaintFox5]

Yes the 2 wires I have one says don't splice on it ..but I did indeed splice the end of it to the other wire per this diagram if that makes since ? Is this correct? I wired up my ignition per this diagram. Which brings me on to my next question I got the painless dura spark harness but since it's a conversion after Market harness should I not wire it up per the instructions since I'm retaining my factory wiring should I use the wiring off the super motors diagram , hook the red with green stripe from the fire wall to the positive side of the coil ? Thank you in advance I'm close to getting it fired off got the first time in 4 years now

 

[DirtDonk]

Yes the 2 wires I have one says don't splice on it ..but I did indeed splice the end of it to the other wire per this diagram if that makes since ?

Is this correct?

Not yet, but I'm sure it will soon...;D
What wire did you splice into the "do not splice" wire?

I wired up my ignition per this diagram. Which brings me on to my next question I got the painless dura spark harness but since it's a conversion after Market harness should I not wire it up per the instructions since I'm retaining my factory wiring should I use the wiring off the super motors diagram, hook the red with green stripe from the fire wall to the positive side of the coil?

What instructions? The ones with the Painless ignition harness? The diagrams are the factory setup and the Painless harness should not vary from the factory layout. Or if they do, it should not be by much.

The Red w/green indeed goes to the ignition coil's positive terminal. But only after it passes through (not bypasses) the existing resistor wire under the dash. Which is the one that says do-not-splice.
If you connected it to that wire after it passes through the firewall then you should be good.
The little squiggle in the Red w/green is indicating a resistor. Any wire attached to the ignition switch side of that wire is bypassing the resistor, while any wire connected to the other end of that wire is getting lowered voltage due to the added resistance in the wire.

Got any pics of what you've done?

paul

 

[IllpaintFox5]

Looking at the diagram I spliced wires 16 Red w green and 904 green w red, I spliced them together to the back of the ignition switch. Does this sound correct? More pics later today the painless harness is out for delivery now so I'm going to play with it this evening, and I will post more pics. Thank
You

 

[DirtDonk]

Hey there. Sorry for the delayed response. Been on the forum a few times since you posted, but from my phone I can't see the diagram well and wanted to wait until I could.
I thought I knew what 16 and 904 were, but mis-read your post and thought you said both were Red w/green. My mistake.

I must have missed something though. Were they not already spliced together at the switch? The switch is still original wiring, and you're just adding the Dura Spark harness, correct? If so, then there should already have been a #904 at the switch and running throughout the harness to things like the voltage regulator. And anything that needs power in ON only, and not in ACC key positions.

So your old #16 to the coil would still be in place, utilizing the resistor section. Your new #904 could splice into the old #904 to get power to the new ignition control module. But you'd splice it to the #904 (anywhere in the wire) and not need to cut or compromise the old #16 in any way.

You just need to end up with power to the ignition coil through the resistor wire when the key is in the ON position, full 12v to the ignition module when the key is ON, and the other new wires connect the ignition module to the distributor and to the negative side of the coil.

Is that how yours is laid out now?

Paul

 

[IllpaintFox5]

Hey man so if you go to my post number six I think basically the bronco came with a push button start and a HEI rigged up. I was just making sure I was suppose to splice them two wires together because they had a push button so I had to identify the wires and the diagram and makes sure I wired it up right is all but, sorry for the confusion , I spliced 16 and 904 to each other then butt connect to the single Red w g wire on the ignition pigtail in post number 6. So yea the painless kit came with some extra wires as if you never had a duraspark set up. Here are my connections. Set the timing to 10* on the crank rebuilt the carb 2150 2 barrel new “42” plugs and new wires, I drove it for the first time 3 speed on the tree it had no breaks right now but man the motor runs great ! Need more work but atleast turn key

Factory brown and red with blue stripe at starter relay

Factory red with green strip comming out driver side fire wall connected to painless + ignition coil

Factory blue and red w blue stripe going to the ignition module plug n play

Only have two extra wires left and one is for a tach wire yellow and the brown would be the starter solenoid ignition post but I'm not running it , could I use this wire for anything else ?

The purrrdyyyy side needs rear flares

Need to work on battery cables power steering leak breaks , they only have one thick wire running from the alt to the battery I'm guessing this needs a mega fuse they have the factory alt wiring zip tyed up should I get a stock alt or keep the one I have and add a mega fuse ?

Here is the alt one big red wire to the Batt terminal is all they had

Probably made this more difficult wiring isn't my specialty made more since with parts bolts on first and looking at both diagrams

Thanks for the help man

 

[DirtDonk]

Hey man so if you go to my post number six I think basically the bronco came with a push button start and a HEI rigged up.

Ah yes, I remember that now. I should have re-read the earlier posts because I tend to quickly forget whatwherewhenandwhy with each Bronco!

Set the timing to 10* on the crank rebuilt the carb 2150 2 barrel new “42” plugs and new wires, I drove it for the first time 3 speed on the tree it had no breaks right now but man the motor runs great!

Holy cow, a milestone! Nice to hear it purr I bet.

Only have two extra wires left and one is for a tach wire yellow and the brown would be the starter solenoid ignition post but I'm not running it, could I use this wire for anything else?

I would not think so. It's connected to the ignition, so has voltage when the key is ON. But it does not have a full 12v all the time, so would not work with most accessories. And you really don't want extraneous devices connected to the positive side of the coil anyway. Too many chances to have trouble.

...they only have one thick wire running from the alt to the battery I'm guessing this needs a mega fuse they have the factory alt wiring zip tyed up

...should I get a stock alt or keep the one I have and add a mega fuse?

A Mega-Fuse would future-proof the setup, but you could get away with a smaller Maxi-Fuse setup depending on which alternator you're using. Do you know if it's a 45a, 50a, 55a, or 60 amp model?

Not sure what you mean by getting a "stock" alternator. Looks like that's what you already have. Is that not the case? Do you know whether or not this one works yet? If not, don't just buy a new one yet. Check this one and connect it accordingly to see if it will work out.

Are all the other wires there still with the harness? Your ammeter gauge in the instrument cluster will not function properly with that charge wire connected directly to the battery, but you should still be able to get a charge out of the alternator. After you connect it all, measure the voltage at the battery while the engine is running. Should read approx. 14.5v or so.

Paul

 

[jckkys]

I've been trying to follow this thread and see a few points that I have to clarify. First the stock Duraspark was the most dependable you could use. There's no reason to change individual components for convenience or some weird idea that other systems did things differently so injecting those parts into a Duraspark ignition would improve it. That's pure BS. 12 volt coils were available throughout the Duraspark design process. The Ford engineers chose reduced voltage and built the whole system that way. The result is a very dependable and long lasting product. There is no reason to think more voltage would help in any way. The voltage delivered to the plugs is more than adequate and has been for 45 yrs. The horse shoe connector has been functioning faultlessly for at least 47 yrs. The coils made for them are readily available and are the part any parts store would offer for Duraspark ignitions. Several posts mentioned more than 2 wires to the coil. I can only assume the color stripe on the wires was misinterpreted as multiple wires.
The harness pictured in post#6, that I assume is the painless product, looks the most stock including the color coding. So that would be my choice. If you still have the red resistance wire from the ignition switch, the ballast resistor is redundant and unneeded.
There is an irresistible push on this sight, in particular, to fix what isn't broken. That is likely also the reason you were faced with a huge cluster F when you bought that '77.
Ford never referred to the ignition module as an ICM, so inventing a new designation can only increase confusion. It could also be accurately be called a transistorized amplifier. But why?