[Th3 T0y M4k3r]

This is gonna’ get a little complicated, so bare with me. I’m planning on installing a Ford EDIS-8 (electronic distributorless ignition system) on a 351 Windsor that’s going in my ’68 Cougar. To support the electronics, I’m installing a 93 amp GM 12Si alternator and a new, under-hood fuse box to take a lot of the load off of the old stock fuse box.

The main problem I’m running into is getting power to the coils. Currently, the single coil receives power, during start-up, through the solenoid, then from the ignition switch during running. I need to be able to run two coils instead of just the one and they both need 12 volts (currently, I don’t think the single coil is receiving a full 12 volt charge since it should be running through a dropping resistor).

My first idea was to split the positive coil wire and run each end through a normally-open relay and pull the actual current to run the coils from the under-hood fuse box. I’m not sure how reliable this setup would be and I don’t think it would work terribly well during start-up (the fuse box would have to draw power through the battery’s charging line).

I’ve never tried to play with the ignition switch, but that looks like what I will have to do. Maybe rout the power from the new fuse box to the ignition switch, then out to the coils, but how do I power them both during start-up? Would the solenoid be able to put out enough power to turn the starter and fire both coils too?

I know this is about as clear as mud. If you need the wiring diagrams that I’ve come up with to make sense of all a’ this, let me know.

Oh, and any other advice would be good.

[BillyJoe]

Try this website and associated ones for 'MegaJolt'. At some point I want to try this as well with my Ford 302.

http://picasso.org/mjlj/

http://www.megasquirt.info/allQs.htm

The MegaSquirt is for fuel injected engines but there is useful info there...I asked about this stuff here before but nobody seems to know about it.

[Th3 T0y M4k3r]

Thanks for the reply. I’ve already been through most of those pages; they really don’t go into much detail about how to wire the systems. I’m about ready to just rout the coil power wires through a pair of toggle switches on the dash and be done with it. Trying to rout all of this stuff through the original ignition wiring is worthless anyway. The whole system is 36 years old and underpowered. I’d probably be more likely to start a fire than get the car to run.

What are you putting the 302 in? You do know that the Ford Exploders… er, um make that Explorers equipped with the 5.0 L’s had EDIS systems on them from the factory. If you don’t mind running with the explorer timing cover, accessory brackets, and the 50 oz balancer, everything will bolt on.

[NXS]

-Yes, I would like to see the diagram. if you know what is supposed to be hot and when it is then it should be easy.

-I'm not much of a ford guy but wouldn't it take a minimum of 4 coils to run distributorless ignition v8?

====================================
Two coil packs...Tracking like a scud missle Sir!

I’ve never tried to play with the ignition switch, but that looks like what I will have to do.

On your ignition switch there should be at least one wire that is Hot during both RUN and Strat posistions. That wire should power both coil packs. Run a fresh wire to them with a splitter like you said earlier.

Or you could do as you said and use a relay powered by the current +coil wire. One coil wire and one relay. the split would need to be after the relay powering both coil packs. Also it should be run from the Battery(not the starter side of the solenoid) with an inline fuse as close to the Battery as possible.

if you need pics let me know

[KULTULZ]

-This discussion- may give you some ideas. If you are not using EEC, it seems you need to find an early installation which runs off an ignition module.

[Th3 T0y M4k3r]

I actually have three diagrams. The first is the basic charging circuit as well as a partial cranking circuit. I’ve gone ahead and labeled a few of the major parts.

[Th3 T0y M4k3r]

The second shows most of the power circuits that will be routed through the new under-hood fuse box; you’ll have to ignore a lot of this stuff. I’ve labeled the wires I’m having trouble routing. As you can see, I’ve run the two coil packs on separate lines through the fuse box; this is in hopes of providing as much power to them as possible. Is this not such a good idea?

[Th3 T0y M4k3r]

The third is the rest of the EDIS system wiring connections if anyone is interested. It shows the proper spark plug wire path for a Ford 351 Windsor.

[NXS]

Kind of hard for me to see each wire, but for what i could see you'll have no problems. I suggested one relay for simplicity, but two could help you limp home in the case of a bad relay.

[Th3 T0y M4k3r]

Sorry, I didn’t ralise the diagrams would come out so small. You could probably download them and open them with paint. That would allow you to zoom in for a better look.

Also, would it be easier to rout the coil wires together on a single line instead of separately like I have in the second diagram?

[NXS]

From what I can see it looks like you have them ran together in diagram#2.

I think you'll be fine. Maybe just swap the #7/4 & #6/1 plug wires on the coil packs for looks.

[Th3 T0y M4k3r]

Wow, my diagrams must be pretty bad; they should be two separate lines. I guess I should make the wires wider than two pixels a piece, then maybe you could actually see ‘em.

So I should run a single line with a single fuse to feed both coils, right? Should I use a heavier gage wire from the fuse box to where the line splits off to the coils, or should I use the same gage the whole way through.

Wish I could reverse the plug wires, but I can’t. They have to be run in that exact order or they won’t fire when they’re supposed to. It’s gonna’ be a little ugly, but that’s why I decided to separate the coils, that and the shorter plug wires.

[NXS]

your firing order is:
1 5 4 2
6 3 7 8

You have four coils. Coils 1&6, 5&3, 4&7 and 8&2 fire in pairs. The mounting points you have choosen will allow you to run your wires like this:

[Th3 T0y M4k3r]

Oops, you’re right. I forgot it was a wasted spark setup there for a while.

Funny thing is I had it diagrammed the other way for a while until I picked up a set of coils. It’s got the cylinder number marked on each tower so I went ahead and “fixed” the diagram. I guess I’ll have to fix it again.

[NXS]

Your diagrams look very detailed. I would really like to see your completed project!