Centech Harness questions... Here's a tip!

[Viperwolf1]

Do you get 12V to the P terminal when the brakes are pressed?

Check front right light ground.

 

[Nightstick]

I put some small strips on tape on the switch where it contacts the rod, and it works fine now. You're welcome for the play-by-play ;D

 

[Nightstick]

Do you get 12V to the P terminal when the brakes are pressed?

Check front right light ground.

I'll check that ground now, thanks!

 

[Nightstick]

Silly light bulbs %)

So I have one bulb that works. It was in the left front turn/park socket and worked fine. On the other, only one filament would illuminate. Switched bulbs and the right works fine, left doesn't. I have like four bulbs sitting around and only one of them works properly apparently. More than likely the bulbs I have are brake lamp bulbs, are they the same bulb?

 

[Viperwolf1]

They are the same, #1157.

 

[Nightstick]

They are the same, #1157.

I thought so, hmm... I'll pick up another one tomorrow and see if I just have bulb issues. Thanks

 

[Nightstick]

Alright, so I dropped Izzy's old motor in the bronco, and I have the duraspark to hook up. Initially it was wired as a points/pertronix ignition, and I've read over the Centech instructions, but I'm just not good a deciphering written instructions %).

As you can see in the first pic I have what appears to be the original three wires coming out of the dizzy, but about a foot down the wires it get's pretty messy. So the problem I'm having is the end of the wires has an old three pin connector and one of the connectors that go to the module connected to it as well. A connector on the module is toast too.

I'm gonna get a new module, should I get a new dizzy as well? I'll get Izzy to post some pics of the connectors connected to the dizzy end, so y'all can see what I'm working with. Not sure how this thing ran properly in Izzy's bronco!

I guess the main problem is I don't know if the connectors that are there are in the right place and wired properly, so I can go by the centech instructions and wire it that way.

 

[DirtDonk]

Man, that's some melted up stuff, eh?

Pretty straightforward in some respects. You can see on the module's 4-pin connector the wire colors that match the distributor. The one odd one, the Green wire, goes straight to the coil's negative terminal and is what tells the coil to fire. Just like the Black wire from the old Pertronix and Points.

The (vaguely) Black, Orange and Purple wires match up to the distributor's wires. Black is the ground, and the other two are the signal wires from the magnetic pickup.

The Red and White wires are for power. But there's where it gets confusing.
Key-on ignition power can go to either one, depending on which module you have.
Start-only AND key-on power can go to either one, depending on which module you have.
Basically though, most should run just fine with a simple 12v key-on wire to the Red wire. I've run them with keyed-on power to either one, and they've run.
I had one with the White wire as the power, the Red wire had a start signal, and it ran just fine.

So for now, run the other wires and wait for Viperwolf to tell you which one can go where. I have diagrams showing both ways, but they don't specify a grommet color. Only a year model.

And speaking of which, is this the '74? Or some other year? I see what looks like a small cap Duraspark dizzy, so I thought I'd ask. Some of my diagrams list '74 as a Black grommet year, which would have had a 3-wire plug and a 4-wire plug. Not the 2 and 4 that you're showing.
Just checking. We can make it work no matter what you use, but I want to make sure everything is kosher first.
Before you order your module, lets make sure what you need. It's likely you'll no longer want to order one specifically for a '74, if the Black grommet is what you had. The Blue Grommet one seems to be the default retrofit for these types of restos. What with a whole new harness and all, you can pretty much choose your poison.

Paul

 

[Nightstick]

That helps a little Paul, but it's also the part that confused me... If the green wire goes straight to the coil I would think it wouldn't run through the connector, and just have a ring terminal on it. Should I just cut it behind the connector a s run it straight to the coil?

Unfortunately the bronco is at Izzy's house so I'm not looking at it. If I remember correctly though, the gaggle of wires coming off the dizzy have wires running to coil + and -... While I'm typing this I suppose that the connector that's wired into the dizzy has a green wire going through it and to the coil. What would be great is if I could simply replace the connectors themselves using the existing wires from the module and dizzy as I know both work cuz they did on Izzy's bronco.

His bronco is a '76, but no one can say for sure if the setup was original to his bronco.

 

[Explorer]

This should help. Connectors are available at NAPA.

 

[Nightstick]

Awesome!!! I'll swing by there today, thank you!!!

Edit: Well crap, I got a new module from autozone that has good connectors, but they would have had to order the individual connectors for the dizzy side, NAPA is closed!

 

[Viperwolf1]

This should help. Connectors are available at NAPA.

Napa has the female 3 and 4 pin plugs, not the module or distributor side plugs. Those are only available on replacement parts.

3 pin – Napa ECH EC72
4 pin – Napa ECH EC127

 

[Nightstick]

Napa has the female 3 and 4 pin plugs, not the module or distributor side plugs. Those are only available on replacement parts.

3 pin – Napa ECH EC72
4 pin – Napa ECH EC127

I'm confused again (this would be a lot easier if I had it in front of me). So I have this right, the module and dizzy both have male end connectors? Looking at the diagram Explorer posted that appears to be the case, and it looks like there is a female end cable that runs from the module to the Dizzy connector four wires going out of module, three going into dizzy with the other one being the green one going to coil negative.

On the two pin module connector theres a female connector that goes to the ignition side. So.... If I have a module with good connectors, and I find a good male connector for the dizzy (which I cannot order just the connector according to viper) all I need is the female ends to make the whole thing work right?

 

[Nightstick]

That rambling post made sense to me, I think i got it figured out. I never saw any female connectors in the mess izzy gave me and it looked like the dizzy was wired straight to the module, that's what was messin me up. Thanks for the help!

 

[Viperwolf1]

I'm confused again (this would be a lot easier if I had it in front of me). So I have this right, the module and dizzy both have male end connectors? Looking at the diagram Explorer posted that appears to be the case, and it looks like there is a female end cable that runs from the module to the Dizzy connector four wires going out of module, three going into dizzy with the other one being the green one going to coil negative.

On the two pin module connector theres a female connector that goes to the ignition side. So.... If I have a module with good connectors, and I find a good male connector for the dizzy (which I cannot order just the connector according to viper) all I need is the female ends to make the whole thing work right?

In the diagram that explorer posted above, the female connectors have white colored pins. Those are the ones that Napa has.

 

[Nightstick]

In the diagram that explorer posted above, the female connectors have white colored pins. Those are the ones that Napa has.

Right, I guess my post was a little garbled. There's a total of three female and three male connections.

Module has two male connectors, one four pin, one two pin. Dizzy has one three pin male connector. The wiring between the two components has all female connectors. Female connector plugs into the four pin module side and as is makes it's way to the dizzy the green wire splits off going to coil neg, then into the male dizzy connector as a three pin. Two pin connector goes to the ignition switch.

 

[DirtDonk]

If the green wire goes straight to the coil I would think it wouldn't run through the connector, and just have a ring terminal on it. Should I just cut it behind the connector a s run it straight to the coil?

Unfortunately the bronco is at Izzy's house so I'm not looking at it. If I remember correctly though, the gaggle of wires coming off the dizzy have wires running to coil + and -... While I'm typing this I suppose that the connector that's wired into the dizzy has a green wire going through it and to the coil. What would be great is if I could simply replace the connectors themselves using the existing wires from the module and dizzy as I know both work cuz they did on Izzy's bronco.

His bronco is a '76, but no one can say for sure if the setup was original to his bronco.

There's a total of three female and three male connections.

Module has two male connectors, one four pin, one two pin. Dizzy has one three pin male connector. The wiring between the two components has all female connectors. Female connector plugs into the four pin module side and as is makes it's way to the dizzy the green wire splits off going to coil neg, then into the male dizzy connector as a three pin. Two pin connector goes to the ignition switch.

Correct. What's apparently missing is all the harness in-between the fender-mounted module and the engine-mounted distributor and coil. (edit: nevermind. I see you still have the wires, but not the plugs.)
And the reason the Green wire is in the same harness (as you've probably already figured out) is that Ford puts the coil right next to the distributor anyway, so why not loom them together until they need to split off just before the distributor's connector.
That way the two coil wires can run through the same central harness and branch off just there, where they run up to the coil in it's "horseshoe" connector.
The horseshoe is why there is no ring terminal too. Duraspark coils use a unique-to-Duraspark slip on connector.

The '76 distributor would originally have had the larger cap with male "spark plug" type terminals. Someone either swapped out the dizzy, or just robbed the larger cap and cap-adapter that allows the early style distributor to run the larger cap and rotor.
Maybe a PO only had an old set of wires, or was just cheap and didn't want to pay for the more expensive later wires, cap and rotor, so just down-graded the components instead?

I think you got all that already, but thought I'd re-hash it to confuse things.

Paul

 

[Nightstick]

The coil that was used when it was in Izzy's bronco was a standard type but an Accel super-stock. It worked fine with it, whats different about a duraspark specific coil?

Edit: the horseshoe type terminal doesn't screw all the way off and therefore a ring would not fit over it? I'm assuming I could put a ring terminal on the green wire and use a standard coil right?

 

[DirtDonk]

Outwardly, not much. Just the terminals and (sometimes) the color.
But internally, the most likely reason for a change in terminals was a possible change in internal resistance values.
Not saying that Duraspark coils definitely had those changes (though easy enough to verify I would think (just ask Viper)), but that it's possible.
Or maybe Ford just decided it was time to eighty-six the old designe and put something more "modular" and quick-disconnecty into their designs?

Don't know, but in almost all cases, the ignition coil, whether O.E. or aftermarket, is matched to the ignition type/variation/voltage with the proper internal resistance.
If your Accel coil is the proper type, then there's no real reason to change. But if you can see a part number, it wouldn't be a bad idea to go to Accel's website (recently screwed up by the way) and make sure that it's the correct one for a Duraspark with no resistor wire.
If not, you would either add a ballast resistor, or change the coil.

Paul

 

[Viperwolf1]

All duraspark coils have the same internal resistance as the older points type ignition coils. Therefore the voltage amplification is the same. In '76 the ignition resistor value dropped about 30% which increased coil current and spark voltage. That change probably made the larger cap and adapter necessary.