[wbnapier]

Hello,

'65 GTO, with 455, '65 Tri-Power, MSD Dizzy, 6AL box, blaster 2 coil.

I had an electrical short that resulted in the car dying as I backed out of the driveway. There was smoke emanating from under the hood after a few failed restarts and I found a frayed wire had shorted, the current jumped to another wire and they melted together. See the first photo. All fixed and I have driven the car twice.

Today, it died on me twice, but I was eventually able to limp home.

I pulled the main coil to dizzy wire and noticed some minor melt. See the second photo.

I've pulled the coil and measured ohms. Primary 0.7 - 0.8 ohms. Secondary 5,800 ohms.

Any opinions? I have very little experience with electrical. The wiring is 25 years old. I'm thinking of replacing the entire wiring harness and making everything nice.

[Scott65]

I believe those two wires in the first photo are supposed to be two separate wires from two different sources. The yellow/blk I believe should be full 12 volts, the other is a resistor wire and should begin black with red or pink stripe. Not sure about the colors, but they shouldn't be spliced together. The full 12 volts is for cranking, and the resistor wire is for run, both power for the coil for different purposes. That being said, you should only need one now, for the msd, and it should be full time, full 12 volts. Hopefully someone else will interpret your coil resistance values.

[wbnapier]

Thank you Scott,

When I dug into the engine harness last time, there was all sorts of confusing things. You should see how my alternator is wired! I think I need to bite the bullet and re-wire from the fuse block forward. I'll post some more photos in a couple of hours.

[Bill Hanlon]

Originally Posted by wbnapier

I've pulled the coil and measured ohms. Primary 0.7 - 0.8 ohms. Secondary 5,800 ohms.

Those are proper values for a Blaster 2 coil.

[Scott65]

I don't know what kind of shape the rest of the harness is in, but those two wires can be replaced at the bulkhead connector. I did it years ago to get rid of the resistor section. Nowadays, I have those two wires run to a junction block, and have a source for 12 volts hot in crank and run position of the key. I use it to power relays now so it doesn't see much load. The alternator wiring is pretty easy to re do also. The master splice was in amazingly good condition on my car, but i completely replaced it all with stuff from MAD electric anyway. Not trying to discourage a new harness, but it may or may not be necessary to correct your issues.

[wbnapier]

Do you by chance know where I can buy a 10 hole bulkhead connector? I think they are called series 56 Packard.

[wbnapier]

Update... I received the spark plug wires, cap, and rotor today. The spark plug wires are for a 4 cylinder. So I need to return them to Summit.

I really wanted to do this over the weekend, so I think I'll try Napa tomorrow.

Can you guys recommend a MSD set that works with Pontiac and my MSD Dizzy 8563 and MSD 6AL 6420?

Thank you.

[wbnapier]

I just called Summit, and they will overnight the correct set and eat both the overnight freight as well as the price difference. That's a win! I should be ass deep in this sometime tomorrow.

[wbnapier]

They set me up with a different MSD, https://www.summitracing.com/parts/MSD-31363

Thought?

[HWYSTR455]

These are my go-to wires, MSD super conductor, multi-angle boots, universal:

https://www.summitracing.com/parts/msd-31193

.

[wbnapier]

It helps to hear different viewpoints. In my case, limited time, skill, and with those wires being 25 years old, I'll replace them.

I admit, I sometimes throw parts at a problem, as opposed to doing proper diagnostic work. Lack of skill

I've ordered pretty much everything. I'm hoping to have it all by Friday and be able to do/break something this weekend. I'll keep the thread updated.

[Scott65]

No, I only replaced the wire/connector. The bulkhead itself still functioned fine on mine.

[HWYSTR455]

The Packard bulkhead connectors and fuse blocks are not available individually, they only sell a min of like 500 or 1000. I tried. You can salvage some from a boneyard though, or someone who has replaced their engine/forward light harness.

The Packard connectors are 56 type, readily available at any auto wire warehouse online. Many also sell the open terminal crimp tool, the Casper one is fine (@$30).

https://www.waytekwire.com/item/419/...Crimping-Tool/

Wow, when was the last time the plug wires have been replaced? The coil one specifically?

Anyway, yeah, if the engine harness is dated, and has previous damage/mods, you may want to seriously consider a replacement harness. You can have valuable options added, like an 'HEI' upgrade which removes the resistor wire, internally regulated alt, and similar options.

That will give you a line in the sand, and remove many of the areas that are in question. Also would simplify any troubleshooting and repair. (It's much easier to replace the engine harness than it is to troubleshoot and repair).

You say 'it died today, but was able to limp home'. How did it die, it just cut off like a light switch, or it was sputter and chug and fizzled out? What did you do to limp it home?

.

[wbnapier]

HWYSTR455,

I will answer your questions/comments, then give you an update:

I purchased some female Packard 56 ones from both Pep Boys and Amazon, and they are about 2m shorter than the ones in my bulkhead connectors. We reused the one connector on the melted resistor wire we had to remove to be sure it had the depth into the fuse block.

It's amazing those bulkhead connectors aren't available.

I will bookmark that crimping tool, thank you.

To my knowledge, the spark plug wires are early 90's and have about 16,000 miles on them. I have no idea if they need to be replaced. I replaced the coil about two years ago, but never the coil plug wire. The car would intermittently stop revving over 4,000 rpms. Replacing the coil fixed that issue. Please let me have your opinion on the wires. I can send photos if you like. The spark plugs are new R43S, gapped at 0.045,

Yes, the engine harness is dated, and yes I ordered a new one from M&H. Unfortunately, they didn't have the HEI modified one, only standard. But, they are including a wire to replace the resistor wire. The salesman said this is the only difference. I will simply ignore the wires for the old 3-wire ext. regulator alternator. Additionally, I ordered a front headlight harness from Ames, which is from M&H, but M&H didn't have stock, so I went to Ames. The headlight harness should include horns and parking lamp wiring too.

Because I like spending the maximum amount of money, I also called up Mad Electric and bought a kit from them for headlight relays, electric fan relays, alternator wiring, diodes, and God knows what else.

After Labor Day, laboring on diagnostics for hours, I am 100% on board with your assessment that it is much faster to replace everything.

Yes, on Saturday the GTO died leaving a friend's house. Just cut off. I started it and it idled for about 10 seconds then died. It wouldn't start for a couple of minutes then somehow started and I drove around the block and it cut off again. A couple of minutes later I was able to restart and make it the four blocks to my house. The cut off was the same type of cut off as the previous short on the resistor wire.

I'm about to download installation docs for my AutoMeter Sport Comp 3.5" tach, my MSD 8563 Dizzy , and my 6AL 6420 ignition box. I have an automotive wiring book on the way and good instructions from M&H too.

Let me know what you think about the spark plug wires.

[Scott65]

Sounds kinda like vapor lock symptoms...

[wbnapier]

It wasn't that hot out, maybe 75, and I have the special spacers between the carbs and intake. I thought it maybe was something like that, but I've never had any issues before. To be honest, I really don't know what it's like to have vapor lock.

[Scott65]

Also, you can check the general condition of your plug wires with a multimeter. Check resistance. Its helpful if you check them when they're new, but you'll get a general idea even if you didn't.

[wbnapier]

What would be the correct ohms/foot for MSD spark plug wires?

[wbnapier]

Update:

I Removed the spark plug wires, cap, and rotor. I've added a new cap and rotor, as well as laid out the spark plug new wires. Tomorrow I'll cut, crimp, test ohms, install and start the car. Then on to the wiring.

I was disappointed to find a fair bit of corrosion inside the distributor. Photos attached. What do you think?

Any opinions on dual crimp vs. traditional crimp spark plug wire terminals?

Also, this morning I checked out the M&H engine harness and compared it with my wiring diagram from www.classiccarwiring.com. I was confused to see a black wire in the #6 terminal location of the engine harness bulkhead connector, as this is shown as empty on the wiring diagram. See attached photo.

When I checked the wiring diagram from the manual, this black wire is for the heater motor. But, on the www.classiccarwiring.com diagram, the heater motor is run somewhere else through a relay. My heater does work and there is nothing in the #6 terminal location. Any comments?

[HWYSTR455]

You have one of the early MSD distributors before they started zinc coating them. I believe you can call support, and they will replace it for you. That causes ignition issues and is a known problem.

You could disassemble the distributor and clean it up, shoot it with a coating, but it could effect the reluctor and pickup. (Don't spray the pickup). I still think they will replace it though.

Not sure I would trust those wire diagrams from that website, I would be looking at the factory diagrams, which are available, the factory service manual does have diagrams, and is basically a very good reference, pays for itself in time.

I wouldn't worry about the diagram, since everything is working. They probably used a generic or 'chevy' diagram.

The 'dual crimp' wire ends are fine, and prevent the core from breaking during installation. If you're making them yourself, push down on the core with a needle or something so it is captured during the crimp, and you will be fine.

.