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Discussion Starter · #1 ·
I was driving to Pittsburgh on my way to school, and at about 11 PM, 60 miles from the destination, the entire electrical system in the car took a dump. EVERYTHING. Headlights, ignition, you name it! I checked all fuses, all were fine. I opened the hood, and the power line from the battery to all the components was gone. It was melted away. I strapped another wire on (had some in trunk), and it melted in two seconds. This would lead me to believe there's a short SOMEWHERE in the system, and before the fusebox. Am I correct? I was gonna go through everything with a multimeter and look for shorts or bad connections. What could it be? Can anyone suggest where I would look? Any help would be greatly appreciated. Thanks.
 

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So no fuses blew? My guess is it is on the engine side of the fire-wall. What size gauge wire did you "melt". Could it be your main starter wire that runs down by the motor, got hot and shorted out?

i had the exact opposite happen. After a while all voltage would be lost, BUT mine was do to an OPEN in the system from the main power to the firewall.

It just has to be a mechanical failure! Maybe your voltage regulator went? As did mine once. it put 20 volts on my wiring and fried a radio and heated up some other wires.

good luck chief

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Start at the terminal on the horn relay and take all that stuff loose and see what happens. Then apply power to the fuse block and work back toward the battery area. Also, for safety reasons it would be good to use a battery charger to power the system so that you are not working with full battery current.
 

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Discussion Starter · #4 ·
Mike, I'm pretty sure the starter wire is good. but I'll check it too. Melted an 8 gauge. There was previously a 10 gauge deal there. I have an internally regulated alternator (two wire thingy), so I'll disconnect it and check. Thanks for all your help. None of the fuses blew. So I guess that would make it a little easier to find, cause there's less junk to go through. I figure I'll pop all the fuses out first and see if the problem persists. If it does, it's before the fuse box. If it doesn't, I'll pop a fuse back in at a time and see which circuit's the guilty culprit. BTW, is the horn relay the first thingy in the system after the battery? I have no idea where it is!
 

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yes, it should be mounted to the radiator support by the drivers side head lights
 

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What year Chevelle?

The typical setup is this:

BATTERY (+)terminal has (2) wires:

Big fat one directly to the starter

Little "squishy" 14 ga. fusible link that runs to the junction block behind the battery next to the radiator. This is the master protection for the whole car--in case something like what happened to you.
After it (12 volts) leaves this junction point it goes into several different splices, other fuse links etc.

But basically it goes DIRECTLY TO a horn relay lug, Directly into the terminal on the back of the Alternator and directly into the #3 terminal on the voltage regulator And lastly into the bulkhead connector feeding the fuse panel.

If you have A/C, the "high" speed relay has it's (+)lead hot all of time as it shares the same lug as the where the (+) 12 volts from the battery comes from on the horn relay.

Be safe, check one thing at a time, take notes. The above post have good info. Don't connect the car battery back into the circuit till your sure you are safe. Several hundred amps is what a battery is capable of--sever burns, fires, etc
be safe! and good luck!

Joe
 

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Isolate circuits, starting at the horn relay as Coppertop said. What you'll be doing is eliminating circuits and components from the electrical system, one at a time. Don't forget anything, alternator, regulator, etc.. Let us know what you find.
 

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Discussion Starter · #8 ·
Thanks, guys. I'll be starting the work real soon, but it's my first week of senior year, and it's hectic. I should have it done by this weekend. Thank you for all the information. I'll give it my best shot. I'll tell y'all what happened by this weekend. BTW, 70 Malibu, originally A/C, but no longer there.
 

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Same thing happened to my 70--fusible link melted. Easy to replace.
 

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Discussion Starter · #10 ·
Easier than that. What happened was when I installed a new 4-core rad, which was much fatter than the 2-core stocker, it pinched the wire running from the junction block to the relay on the other side of the rad. After 500 miles, it rubbed through and caused a short. I noticed it real fast, moved it to a better location, and wrapped in in electrical tape just in case. Car fired right up, all electrics work fine again.

I also replaced the fusible link with a 12 gauge wire. Is that OK, or should I find a fusible link anyways just to be on the safe side of things?

Again, thanks for all your help, guys!
 

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REPLACE the fusible link a.s.a.p.That's why many cars are still around, these are saftey devices for just such a disaster. Go to the nearest auto parts store, the correct one you need is a 14 ga. FUSIBLE LINK, I recently bought a spare, It said GM FUSE LINK. Make sure you get the right guage. Typically fuse links are (2) sizes smaller than the line they protect. That's so they blow up first, and not the car!


It will typically be a "splice on", meaning you'll have to run a little bit of standard wire (use 10-12 guage) from the battery (+) terminal just long enough to splice to the fuse link. Keep this wire close to the battery cause it's just a wire and offers NO protection. The fuse link you get will have a round lug on the end. This connects to the junction block behind the battery, the other end might be bare, or have a butt connector already crimped on it. This is where the regular wire meets the fuse link. Connect it GOOD! You might want to wrap the splice in tape as well to keep moisture/dirt out as remember, this is the lifeline of the whole car.

Good luck, and if you have any trouble, just post it. I think I'll post a pic of fuse link here so the whole world can see. There's nothing mysterious about them. If the parts store doesn't have 'em, go to the next one. "Cause it ain't just a plain 'ol wire"


Joe
 
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