Hello, This form has already helped me out alot and I do not wish to antagonize the members with already gone over issues but I have gone back in your archives and cannot find answers too what I can't figure out. (the name right?)

I have a 1979 F250 4x4 with a 390 in it. To the best of my understanding the last 390 motors were put out in 1976. The Ignition and wiring have/has been modified extensively to the point of sheer mayhem under the hood at the time of purchase. Having soome durspark experience and not really paying attention to how the spider web of wires came out, I now am not sure how to hook up the SOB because the Duraspark box is there (not sure if it was hooked up) right up the fender wall from it is a 4 pin HEI (unnamed). The Coil is a MSD high Vibration.

I am unsure where to run the coil positive wire for trigger, starter solenoid would be my guess but then what is the good ground? I see in threads alot of folks are simply using the battery. The fella I bought it off told me he had it wired through an ACC area of the fusebox. (which I am not going to do)

From what I have read, the duraspark box is unnecessary with this setup? I am not sure where to install fuseable links between alt/batt/coil/.

Once again, I am sorry to rehash old topics but I would be greatful for any help atall.

 

you might want to post a pic of the stuff you have. if you have a msd coil but you have NO msd box (6A, 6AL, etc.) you will still need the duraspark box. to hook up the ignition in stock form you need to verify---
1. the coil positive wire should be a red with green stripe coming from a 3 wire connector around the rear of the driverside valve cover, the other 2 wires are your oil and temp sender wires so follow them if you can't find it.

2. The coil neg. wire goes directly back to the duraspark box not sure of the color.

3. the dist. should have 3 wires coming out of it that go right back to the duraspark box

the msd coil hooks up to the duraspark in the same matter as the stock coil
Do you have a MSD ignition box?

 

Thank you for paying any attention at all. Usually I can handle duraspark because every ford p/u iv had has run that but THIS one....

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In the first one the Wells box (subbing for dura spark is there but the little funny looking 4 pin thing is what I've been told runs this system independent of the dura spark. The coil is an MSD High Vibration and nothing else from MSD. I had to trash the wiring due to an over load under the hood, i mean it looked like some kids with that spray string had attacked it, it was bad. Except when I took it off I wasn't paying close enough attention and didn't pay attention to how the ignition was set up...I have a complete wiring harness from a 1974 390 and it seems like its going to be a good fit except the fuse issue and possibly the where to hook the trigger up.

Hope the links worked, I can't post here and I hardly ever use Flicker.

Thanks for helping.

 

What that looks like is someone took the module out of a Chevy dist and mounted it on the fender well, I'll give em a A for originality, never seen that before. let me check somethings to see if I can get a wire pin out for the Chevy module.

 

Its definitely a Chevy module from a HEI dist, from what I can see from your picture the rear of that module would be your dist wires, there is a + and - for the magnetic trigger not sure what would happen if these were reversed. and to the front, one would be the coil neg wire, and the other the pos wire, were you would also splice in the red with grn stripe from my earlier post, but again I don't know which is which. The best thing to do is get a Chevy dist and take the cap off and follow the wires. Make sure you got good ground from the fender well to the module through its mounting bolts.

 

The Harness itself actually runs directly to the distributor as a plug in as the duraspark would, I'm not much worried about a wire cross except for the trigger, do I use a constant feed or the key switch spring kick feed for the ignition circuit itself, I've been reading about people using the fusebox with this setup and that just plain .... aint gonna fly with me. If thats the case I'll use the left pin on the starter solenoid. Also I'm not 100% about the fuseable link between alt/batt/coil, I know one should be there but im not sure of what needs the most protection.
I just downloaded a MS word file about HEI and its reading good, still a little cloudy about the correct hookup.....

Thanks alot, hope you had a good thanks giving!

 

You will have to have a constat feed that turns off with the key, the wire has to have power during cranking and stay on when the key comes back to on position. I dont know what shape your orginal wiring is in but you can use the red wire with green stripe to power your ignition it has fused links in the stock system. Regarless keep reading up on the GM system, thats what you need to figure out. My thanksgiving was wonderful, I'm checking in to turkey rehab now!

 

Thank you so much for that tip, I knew there was a combo of wires but I wasn't ready to roll the dice and miss the spot. Your explaination of that wire in the harness allows me to feel comfortable about using it as a trigger.

The big problem with this vehicle is that it originally was a 1979 truck, wrecked or something, 390 comes along in ... oh say 2000 or 2001, rehabbed, Air locker installed, axle housings rotated, steering modified (of course) Clement Wheels with 39x18 thornbird swampers....endless. But they kept fidding with wiring most likely because the HEI isn't as reliable as the Wells/Duraspark. As you saw the old style Ignition module is about 14 inches away from the HEI 4 pin. I drove it back from where I bought it and it does alot better then some of the other trucks I've owned. Trashing the wiring was my way of learning that electrical system and fixing some really bad wire connections, The headlights would dim at stoplights and it had some Semi/truck stop style cab marker lights all up the grill....that stuff had to go, all the while I'm doing this not really paying attention....


Thank you again, Kill a lamb tomorrow and save a turkey for me NEXT year! hahaha...I"ll post a few pictures when I get past the initiation posts or something.

 

Ok, NOWWWWWWWWWWW...

Its all wired up....I have spark, it turns over ready to fire and will not run continually....ideas? I am using the post off the solinoid as a kick for the coil instead of the key, not sure if the ground is correct or if I haven't got something else hooked up right.

This is why I'm a dolt.

 

Here is a link for wiring the GM HEI module. Better Dirt Cheap Electronic Ignition