As you read this I am sitting on the side of the road typing away on my phone. I came around a corner and out of nowhere the engine just stopped. I could not start the car. I immediately popped the engine lid and smoke was coming out. Not engine smoke busy nasty caustic smelling smoke from burning wire. I got it out by putting water to cool the wires, ran for my toolkit and got the battery disconnected. The harness started to melt. I disconnected the cooil and it stopped.

Melted harness melted wires. Looks like I may not make it to the car show.

Anyone sell harnesses?

(btw - apologies for the "shit" title, I changed it to "oh crap" and apologize if i offended anyone)

Jeff Bowlsby, and you're lucky

The link you want

http://bowlsby.net/914/WiringHarnesses/

That's the symptom, where's the cause?

No clue on cause just yet. One of the other wires melted on top of it. That's the coil negative, what's going to cause that?

Clean your grounds. Too much resistance.

Figures. I did the battery ground the other day and was going to post up about that. Yeah. I got lucky.

I've also seen that on a bug the owner got the + and- backwards on the coil, FYI.

Ya, but that would go up in smoke right away, you wouldn't be out driving....

Not right away, it did it within the first 20 mile trip though.

Coil wires haven't changed, car has been driven over 500 miles, they're not backwards. But the negative is what went up in smoke. I will dig into it more when I get home. I have to get to work. *sigh*

Here's an odd thing though... as soon as i disconnected the negative battery cable it stopped.

I no more than just MOVED the cable and disconnected a few others and it started puffing up in smoke all over again. I disconnected the positive and it stopped altogether no more. I disconnected the entire coil but it didn't stop till I did so.

Will report back



Not a good start to my day.

Well, once it gets to the melted point, who knows whats melted together in the harness.

Thanks for the scary reminder.....

The late cars with coil mounted to the tin can have the coil rotate and short out against the tin. If you're lucky, it just kills and you shut down the ignition. If you keep the ignition circuit open, it will melt the wires and start a fire.

I love Zambezi Green.

Paul

Glad it was nothing fatal!....always go back over your work
1 or 2 times to make sure it's right!......nice looking ride.
be careful next time!

Well guys - I took a little break before I left for work. The wire melted all the way to the box on the left side of the engine, I assume this is for the ignition? I am hoping nothing burned out in there. But as I look, a ground goes from that box to the wall. It looks like it wasn't bolted down ALL the way and had a washer spaced out but it was barely touching. I am not entirely sure how I missed that, in fact, I never touched it. If that is the culprit, I am unsure how this didn't happen sooner.

More when I get home... it's crunchy down there so I'm ripping it apart tonight to assess the damage. I called Jim to see if he knew someone who could help me tow it but he didn't, he did offer to come help me though. Was awfully nice of him to offer. Hopefully we'll be back on the road soon. I have an extra coil too. I have the extra parts.

I think that is what happened is the ignition circuit stuck open, this explains why the wire continued to burn though and got to part of the harness. It didn't go down the main portion of the harness, just where it splits off to the ignition circuit. I think I can probably salvage it. We will see. I'm not going to do a hackjob (I don't do hack job wiring, and am meticulous with wiring when I rewire things) so if it is, I'm going to get a new harness.

I will report back.

Thankfully I got the smoke and cooking wires out in time.



Yes, absolutely, CHECK YOUR WIRING.



Mine is mounted in a little loop, it shook and rattled but didn't rotate. I noticed that though and used some dynamat to hold it in solid in place to make sure that didn't happen. But what you described is EXACTLY how it happened. Out of nowhere it just cut power. I thought "God i hope that's not the engine" but the rpms dropped slowly like the car was turned off so I knew that wasn't it. It wasn't till I opened up the engine lid that I realized what was happening. Hopefully I won't have to fix much.

Car show coming up!

It is what it is.

Gentleman, appears I have found my problem.

you can run the coil with teh plus and minues backwards with out over heating teh wires, it will make the spark jump wrong and decrease perfromance, but it will not cause the wires to over heat. that is not the cuase.


one reason to carry a fire extingusher. I suggest you all carry one, the bigger the better.

coil mounted to tin can on late cars? what do yo mean??????

I don't know what it will do on a petronix (kill it I imagine), but I do know what will happen with points, try it sometime.

h before e

This is what I noticed right away, as I read on some one else mentioned this issue,...... the coil appears rotated and the melted wires connection appears very close to the tin.. Just my opinion, not a diagnoses.. generally the coils connections sit parallel side by side equal distance from the tin, I see rotation.., intentional or accidental from vibration>?

the truth is with points, the the coil can be run backward (plus and minus mixxed up) and all it will do is change the dirrection of the spark jump.(and make it less efficient) but you can certainly drive a like that with no melted wires.

yes reversing the polarity on the pertronix will ruin it instantly. but with points, the coil polirity while it matters for best spark, wont cuase a fire.

now if the power is sent right to the points cause the points were hookedup wrong, that us different, adn wil cuase melting and fire can take over

Reading this thread confirms my thought that most do not understand points, coil, and condenser electrics!
Tom

I'm not sure where all that came from in the thread since that was never the cause. I posted up the picture of the evil ground as someone had suggested prior. But at least I learn new things in the thread!

I think he gets it, just confussed about if the coil is reversed or if the points are. so long as the points are not reversed and only the coil polarity is reveresed the car will run a bit poorly but it is not a fire danger. reversing the points wire on the coil is when the melted wires start happening. but if it is only the coil, that is reversed and not the points, no fire, just a spark that jumps backwards with less energy for starting combustion. this is basic ignition knowlewdge stuff from long ago

Yep, only a few hundred engines and a couple thousands of tune-ups under my belt...guess I'm still learning.

I have seen this a couple times - to the point that I found myself an earlier mount and put mine on the fan as all the fans are provisioned for the earlier mount. Perhaps, if you are going to continue mounting the coil to the tin you could put a piece of rubber under the business end of the coil. Ever notice how often late tin will be ripped at the coil mount? I think this was a bad engineering idea.

Jeff Bowlsby can recreate your ignition harness. If you want to mount your coil on the fan housing, I think Spunone (Paul) makes or made a coil mount out of stainless.

Hum, so the smoking coil with black spots in the paint wasn't a fire danger at all? I'll remember that.

Sorry detox, didn't even get to respond to this. The rotation wasn't on intention, so if it did it would be from vibration, but i used dynamat to hold it still. I didn't realize they were so close, I'll double check this when I get back in the garage. That is a good point.

First,
Did not mean to offend anyone, hopefully someone will give a detailed explanation of how these systems work and educate the rest of us.
Second,
The coil in the picture looks like a Bosche blue coil. Primary resistance in the neighborhood of 3 - 3.6 ohms. With 12 volts applied to positive connection on the coil and ground to the negative connection, the coil will draw about 4 amps. The wire from the ignition is of sufficient gauge to handle that current all day. Something happened to cause the current to go way up. My guess is the coil is bad, maybe grounded internally from heat stress.
Hope this will help you find and fix the problem.
By the way, when you repair the harness, it wouldn't hurt to go with a slightly larger size wire and use modern wire with teflon coating.
Tom

Yeah I have the original coil, not the blue coil but the original which still works. I also have about 100ft of slightly larger gauge wire, lots of heat shrink wrap, solder and all kinds of odds and ends. Should be easy to make it better than before.

Looks like it started with part of the ignition system. What I am very confused about is that it looks like they melted inbetween and up to but not INTO the relay box. Some very thin green wires melted on one side, the coil wire melted into the other side. Very strange. Pics to come in a few minutes. But the shorts were in 2 DIFFERENT places in the harness. The only thing inbetween? The relay box. I'm sort of baffled. The melted wires did not go all the way into the cabin, just a bit below where the harness heads down the rubber protected boot that goes from the engine bay to under the car....

The other part of the harness was from the coil up to the relay box.

Baffled. Anyone? Thoughts? Was the initial part from the crappy ground? I know I had 2 separate parts of my engine bay go up in smoke, that's what confused me. One with negative disconnected. Then minutes later and it stopped after positive was disconnected.

Alright first off... i'm redoing all the grounds in the engine bay AND rebuilding the harness.



Just so you have an idea of how close this was to a total loss, here's the fuel line, here's the harness next to it. This is after I took it out of the clip holder.



This is when it's clipped in... imagine if that part caught on fire.


Here's a pretty sunset, I kept the garage door open while I worked on my car.




Here's it's intestines spilled over the side of the car. Pretty huh?


Here's the melting point. Oh look, a pun!


This is where all of them threw a party.

Bueller....... bueller............ bueller................................ bueller......

I know that everyone is laser focused on solving the electrical problem here,
... but nobody apparently picked up on this - WATER on an electrical fire!!!!

First of all never throw water on an electrical fire - in conducts electricity & makes an instant ground & connections to everything else it touches!!!!

If anything, the water made it worse, which may be why you're seeing damage beyond the initial harness damage!

Carry a Fire Extinguisher rated for electrical & fuel fires.

Lacking that, you're far better off to throw dirt on it & smother the electrical fire.

That said - first track down the cause(s) of the damage & then resolve those & get a rebuilt harness(es) from Jeff Bowlsby as suggested above, & he restores the engine bay relay boards as well, if you fried that too.

Good Luck on the detective work & repairs!

Good point Tom. I didn't think of that. Hindsight being 20/20, you may be right, that could be what caused further harm. Self inflicted

Is there a testing procedure for the relay boards?

I don't think using water on a 12 volt electrical fire is a good idea either, however, water will not cause the problems you have. Your initial problem was too much current thru the power wire to the coil, which melted other wires in the harness and caused more power shorts to ground. You have a 12 volt power lead in the harness to the coil and to the aar. That is why the harness is damaged up to the relay panel.
Did you check out the coil primary resistance? If it reads good, warm the coil up and read again. It was warm when you had the excessive current. Don't want to do that again, right?
Cleaning up the grounds is always a good idea and replace ANY wire that has damage. When you have all repaired and are ready to test, hook up the positive normally and use a large jumper to connect negative to ground. If possible have a second person standing by to disconnect if there is a problem.
By the way, just for info; an electrical fire is considered an electrical fire only as long as power is applied. Once power is removed, it is a class A fire and water is OK to extinguish. Yes, you will have to clean up, but, you are going to have to do that anyway. If the negative battery terminal is disconnected, there can be no current flow and fire. What your second fire was is heat build up in the harness finally igniting the insulation.
If all I had was water to put out the fire, then water it is, but I do carry a fire extinguisher also. Really don't think your use of water caused any further damage, but make sure you clean up good anywhere the water could have gone.
Hope this has been helpful,
Tom

Indeed it has, thank you Tom.

So it sounds like my issue was the coil and a few other things caused damage from that. Hopefully my relay box is okay. I will be going all out and making a new harness tonight. Most of the wires around it were fine and not at all affected. Others.... not so much. The bigger harness that goes from the engine bay to under the car on the other hand looks like a nice combination of melted cheese and copper.

I have'nt followed this thread completely, but it looks like the destruction started in the ignition harness with the coil wires. 40 year old wiring harnesses in the engine bay in particular (heat) have hardened wires and when they crack, internal to the outer harness casing, they can short and do exactly what this one has done.

Your wiring is damaged on both sides of the relay board. Definitely replace or rebuild the ignition harness. I can ship an excellent condition used one to you tommorrow if you are interested, its on my Parts FS webpage link in my signature block below or I can build you a new one on short order if you prefer. Both with color coded wires! Yum!

The relay board circuits can be checked with an ohmmeter, but it would advisable to remove and replace the potting compound on it (or just completely replace the board) to visually check everything so that damage is not concealed to be sure.

The biggest challenge of this is the concealed damage to your chassis wiring harness. You need to open and inspect that portion of the harness to check the wiring and repalce anything defective. Cut open the casnig and check the wiring in the engine bay where damage is obvious and also follow it upstream into the cabin where the harness is at the center tunnel and further until you see no more damage. Check every wire. Replace your points/condenser, and check the electrical portion of your ignitrion switch.

thanks Jeff. Let me see what I can get done tonight. i got a lot done last night. i have about 100ft of various colors and gauges of wire that I am going to tackle it with tonight. If I feel it's a bit too much or overwhelming, I'll go for it.

I followed it and it stopped melting and causing issues just before it hits the cabin area. I may go up INTO the cabin area and fix it there just to be on the safe side, or replace the wires altogether. I realize it's a lot of tracing to do but I want to do it right, I don't feel like doing it again.

Thanks for all the assistance and advice and help everyone. I am determined to get this done!

Progress

Before.


More before... They were mangled as all hell.


Midway


Almost there.


w00t

Jeff, I might take you up on that relay board just to be on the safe side since I do not know what mine looks like. How soon could you get it here and do you take paypal?

Holy crap! Harness pt 2.

All i can say is.... DAMN!

Sorry to see that!
Is that harness pic the harness with 14 pin connector from the relay panel to the passenger cabin?
If so, it looks like you have more of a problem than first thought.
Did you ever check the coil? Until you can figure out what caused this, be careful applying power.
Tom

It's hard to tell. But I think the main harness was self inflicted. After trying to relive the event in person and piecing it together I think this is what happened...

- First failure was from the coil. The ignition circuit was left open. Negative coil wire (or the one that was black with some purple) melted, this caused the rest of the ignition harness to fail with it.

- I unplugged the negative battery cable. It stopped.

- Suspecting something was horribly wrong with the cable, I unplugged a few of the coil wires to "be on the safe side" literally seconds after I did this the main harness started to go up in smoke. This is where the negative cable up on the other side of the relay box completely melted in half and caused the main portion of the harness to go wild on me. I disconnected the positive, and one more wire on the coil, this is where it stopped entirely.

I should have disconnected the positive first, then the negative, and had BOTH unhooked, but did not. In the moment of being a bit frazzled at the situation, I wasn't thinking.

The only thing i can think of is that because the ignition circuit was still ON that the rest of the wires heated up in that circuit from lack of ground, causing the second failure. So in essence, I had 2 issues. One from a coil issue, the other potentially self inflicted.

This is after seeing the damage and trying to piece it together.

I will check the coil in a bit. I'm still rewiring the entire harness right now. I am almost done.

I did some weight reduction and removed the extra guests tonight that I found hitching a ride in my car. Looks like they expired a while ago. LOL.

Was trying to find an EASY way to get to the harness. In the process... well... yeah. Ended up cleaning my entire floor.



Caption: "Oh gawd help me! It stinks in here!"

OOOOOOOOOOOOOHKAYYYY - perhaps I was way off. I traced it into the cabin area - just to make sure there was no damage. Upon further inspection... i found that one of the wires, a thick black cable (ground perhaps) about 14 gauge was "sticking" to the other wires, not a lot, but a little. I decided to trace it all the way back to the main portion of where the harness enters the fusebox, and sure enough, tons of melted plastic at the fusebox but no blown fuses.



I am trying to trace it back to where it goes. My fuse chart says it's the brake light and turn signal area? It goes all the way through that part of the harness and back into the relay box in the engine bay.

Oddly enough, there is a brown wire that runs along it. That wire melted to the black one and they touched in one spot. The wire (brown one) runs all the way through the main harness and grounds back in the engine bay area along the firewall (the ground on the wall to the left of the relay box). That wire had essentially burned itself in half it got so hot. About halfway into the cabin, it was NOT hot or sticking to anything (probably since it burned in half ) but the black wire never burned in half but did get hot, bubble and stick to other wires. It fused back with other wires in the engine back, and burned up in one spot at the furebox and another spot in the cabin with the same brown wire.

Totally baffled now as to what exactly caused this whole mess.

Ok this is interesting. After pulling the main harness out of the cabin area (which i am almost done with) I found that UNDERNEATH of the harness was CHEWED by these pesky little mice a while back. Lots of the wires were exposed, frayed, etc.... Now... i'm not for certain of this aided to the cause. But after being so insanely baffled by the harnesses going up like they did, it may shed some light.

I am about 75% done with the harness at this point and am almost done with the plug ends for the relay box. I went all the way back through the cabin and into the fuse box, replacing all wires to be on the safe side, and inspecting the fuel lines to ensure they were also not affected (and they were good to go).

ALmost done. Then it's replace the coil, figure out where shit goes and see if she'll start. So close. So close.