Bad Monday! Electrical problem!

[kxmotox247]

Definately a bad start to my day. I hope everyone reads this and maybe learns a lesson in advance of actually having it happen.
I bought another old truck...a 67'...last week.
Anyway, I was on my way to work about 6:30 this morning. I was only 3 minutes from home when I started seeing some kind of smoke coming out from under the hood. I immediately pulled over and the smoke started getting thicker. I popped the hood and the wire from my alternator back to my battery was frying!
Every bit of insulation was completely melted off. I was just praying that a fire wouldn't start up and burn up the truck.
I haven't had a good chance to look things over yet but here's what I think happened:
+12V wire to the battery from the alternator had some extra slack in it where somehow it ended up laying on the exhaust mainfold. The insulation slowly melted off and then it grounded out against the manifold. Once it became grounded, the whole wire fried out like I saw.
To make it worse, when the wire fried, the hot metal strands touched the plastic air-ride lines and melted through in a few spots causing the truck to drop to the ground. The compressor couldn't catch up with the leaks and the truck remained on the ground...on the side of interstate 72...not a fun situation.
Fortunately I was able to get a ride back home to get a trailer to pull it home. The bad part is that no trailer sits low enough to pull a vehicle up on when the air bags are completely deflated. So another trip back home. I had to give in and call a flat bed wrecker. I used a ton of electrical tape to "mend" the lines enough to hold air. Thank god it held long enough to pull it up on the flatbed and get it home.
So here are the lessons:
1) Always carry a fire extinguisher with you. ( I'm an idiot...I have one in every other vehicle and I definately should have had one in an old truck "new" to me) Heck, we have two in the hot rod.
2) Always check over a new vehicle for safety issues such as this. I'm not mad at the previous owner at all. It could have happened at any time and I should have looked things over more carefully.
3) Always carry a roll of electrical tape!
4) Consider installing a battery disconnect to shut things down in an emergency.

Now the hard part comes in. I'm not real smart when it comes to wiring so I've got a huge mess of wires to sort out. My alterator wire melted into 4 or 5 other wires that run across the top of the radiator. I'm sure all of them will have to be replaced.
The truck won't turn over at all now. I'm not sure what else got cooked. Any ideas? Any fuses that would have blown? Fuseable link? Where would it be located? I might have cooked the battery or it's just really dead from running the air-ride compressor trying to fill up the bags.
Tough lesson for sure. At least I'm okay and the truck didn't burn up!
Please be safe.

[Sweet72]

Sounds like a helluva way to start your work week. Have you considered buying a aftermarket harness for the engine bay only? Someone on this board recommended a "cheaper" harness (cheaper than Painless wire harnesses) that was equal in quality.

[Bobalouie]

You will want to check the rest of your wiring to make sure that you didnt melt the rest of the main power wires out as well, or fry your horn relay. once the system goes to ground, the rest of the harness intantly starts carrying that extra current as well.

[kxmotox247]

I can see rewiring the entire truck this winter. There are probably other issues as well. I haven't seen the engine harness for sale. I hate to go with a Painless system...they're expensive. I was just at the Frog Follies car show this weekend and I saw some really nice looking universal wiring kits for about $150. We'll see.
I'll do a pretty good inspection tonight at home. It's pretty obvious which wire burned up...I just want to make sure no other wires went with it!

[Longhorn Man]

I've fried that wire before. I was replacing the alt belt and skipped the first step.
Disconnect the battery.
The alt slid all the way to the loose position and the large post on the back hit the engine. Up in smoke.
A least you didn't grab the wire to pull it off the other wires...even though I got burned...pretty bad, I DID save all the other wires...and skin grows back.
Replace that wire. Get some of the same size, and follow the wire untill it is melted no more, and make sure you get GOOD connections. NAPA has some very high quality crimp on butt connectors that have heat shrink on them already. These are great pieces to have.
Once you replace that, then repair your other wires in the same manor...or go to the junk yard and aquire the whole harness...you know, just for now. Then see if you have power. If you do, then continue with the inspection and try to start it.
If no power, then you have a blown fuseable link...most likely between the battery and the little junction point on the fender. Also check all your fuses before getting on the road.
Your truck is probably OK with the exception of the damage you mentioned.

[stickshift_or_walk]

Can I add a #5 to your list (which I like, by the way)...?

5) Make sure every circuit in the truck (except the big cable to the starter) is protected by a properly-sized fusible link. Quite often amateur wiring jobs will leave these cut out and not replaced (usually out of ignorance), so it's another good thing to check for in any vehicle you acquire.

Here's a site that gives good info on the subject. Oh yeah, and Mark (MAD Enterprises) sells stuff, too .

SSOW...

[Longhorn Man]

Well, most of the circuits have fuses...but there are a few with no links. I don't think the wire that he burned had a fuesable link originally. I have never seen one that does.

And I learned a new one for fuseable links...you can use a wire a couple guages smaller than the wire you are trying to protect, or, you can get the real thing. Go to a junk yard, and find a 6.2 or 6.5 powered truck. look in the pick ups, and the P-30 (bread trucks) and anything else you can think of that may have this engine. Look at the orange wire that goes to the glow plugs. (Think spark plug if you don't knoe deisels) That orange wire is a fuseable link...and quite a bit of it too. Cut all that out of the harness and save it for future use, or as door prizes at partys.

[68w/sbc406]

[QUOTE=Longhorn Man]And I learned a new one for fuseable links...you can use a wire a couple guages smaller than the wire you are trying to protect... QUOTE]
a 18 AWG wire will protect a 16 AWG wire, a 16 AWG wire will portect a 14 AWG wire and so forth and so on

[franko72]

nothing worse than a panic wire burn on the palm of your hand to remind you for about a month how that incident really sucked.I yanked the pos. cable from my 71 camaro to try and save some wires, boy that sure did sting!melted wire insulation is tough on the skin

[71 Blazer CST man]

ya i pulled something almost as smooth the other week. My batt. harnass snapped....and i put it off a day or two, eh heh. Well.. made a left onto a side streen...hit a dip, and bounced back 'n forth(1971 blazer susp.) apparently tipping my bat Back off it's stand and right ontop of the headers!
I was going down the road when, my power steering WENT, breaks - gone, and then the engine started to cut out. ::: sh!T sh!t sh!t:::: ..but kept sputtering for a couple feet ,till it did cut out. Coasted over to the side and my pal and i hop out "aww f!ck sh*t g*d D#mn POS etc. etc." - pop the hood to find my batt. resting upside down ON the passenger side header ::: oh crap ::: - looked at my friend.....and just grabbed it before anything started melting. Put it back, re-connected a wire that pulled apart where it's twisted together - and viola...turned RIGHT over 1'st time.....and we were off again....... Oh yea, it's tied down now.