I was driving my 76 4spd L82 home from work the other day and pulled up to a stop sing and then nothing no power anywhere. Ended up getting towed home by my wife's f-150 I still haven't lived that one down. Anyways, from what I can gather everyone says check the fusiblelink at the starter, but no one can show me what that looks like or where it connects. I need some serious help with this electrical issue. I hate not driving my car. These are the things that I checked.

Alt= in working order
Battery Fully charged

Upon initial inspection I did noticed that the blade style conector on the top of the Alt. had its hot wire broke off, so I soldered and shrink tubed another one on, but the vehicle still doesnt have any power anywhere. Any help would be great and pictures would be awsome.

 

The large terminal on the starter solenoid is where you 12 volt positive cable from the battery connects. The other wires that are installed on the SAME large terminal that your battery cable is attached will have a fusible link made into it. The fusible link will be smaller than the wire that it is connected to just a few inches away from the solenoid terminal. Often times GM used a hard plastic round coupling that joined the fusible link to the larger wire. The large wire size will be the same gauge as the wire on the back of the alternator where it is bolted to the back of your alternator. Fusible links may look like wire but they are very pliable, ( much like a cooked noodle). But do not be fooled. The outer insulatiuon of the fusible link may appear to be OK but the fusible link wire on the indise can be broken or burnt. You will need a voltmeter or 12 volt test light to start to figure out your problem. Call me and I will be glad to help you when you have time.
(704)394-5150 M-F 8:30-5:00 SAT 9:00ish - 4:00ish SUN 10:00ish - 2:00ish EST
"DUB"

 

Yea, the fusible link is in line with the main power supply wire to the Starter stud. It comes from the horn relay dist block- red 10 gauge, near the starter it goes to a brown 14 gauge, then to a red 12 gauge. the 14 gauge is the "fusible link", it probably blew. grab both sides of the brown wire and pull a bit, if it stretches at all, replace. available at most auto parts stores. You'll need a 14 gauge wire (brown). Be sure to disconnect your batt while doing any work on the electrical sys.

 

Here is a pic from Duke94s car and you can see the fusible link. Its a short brown wire with 2 large black plastic connectors on the brown wire-the connectors are going to 2 large red wires.The fusible link is the wire inside the brown wire.
Check it like the guys above described but if thats not it make sure your neg battery cable hasnt corroded off just under your battery bolted to the frame. One other thing to check is the 4 wire connector coming up from the starter -its between the firewall and right cylinder head of the engine-should have 2 red wires,a purple and a black-make sure its plugged together.

 

THanks for the quick responce, I will check the Fusiblelink, as well as the other items, I appreciate the picture it really helped. Does anyone know how to diconnect/reconnect the link

 

You have to cut it out. You can buy new fusible link material, I found it at McFadden-Dale hardware in Las Vegas, but you can also pick it up at Oreilly autoparts.

 

Thanks guys for all the great advise, but there is still an issue. I just got done replacing the Fusible links as discribed by all the post. Battery fully charged and Alt. test just fine with multi-meter. but still no power.

Now I am out of Ideas, I still have no power anyware on the vehicle. I dont know, which direction to go. I was told to take it in, but the towing fees, plus parts, plus labor for elec. work adds up quick. I was thinking of replacing the Engine Harness, Pos/Neg Battery Cables, and the Starter Selonoid extension wire. This would be every wire that comes off my Starter, exluding grounds. If any one has any better suggestions, I am open for your imput. If not those parts then its to the shop.

 

Do your headlights work ? Have you checked the pos post on the back of the alternator for power with a test light ?
I wish I had a better wiring diagram (like one by Doc Rebuild) I think you might have another fusible link either on the left inner fender going to a junction block or it might be under the brake booster at the bulkhead connector-look for the large black connectors like the ones on the other links.

 

Don't tow it, the problem is a simple troubleshoot. First, just below the horn relay, 1/2 way down the drivers side inner fender, there's a 'block" with many wires screwed to it, this is the main power distribution block for the car. test here to gnd for 12V, it's hot all the time. if it's there, next test would be the batt lug in the fuse panel. if good, we can troubleshoot from there. These electrical shops can eat you up in time, but it's your car and time. C.

 

No my head lights don't work, I have no power anyware on the vehicle, and I did find the fusible link going into the back of the fuse block under the brake booster. I will check it and replace it if nessacary thanks for your time.
Got any good tips on replacing it, since it feed directly into the fuse block

 

Is this the block just under the brake booster, if so how do I test it as you were discribing. If it is not the power distribution block then I cant find the block your talking about

 

Hopefully if it is burned there is enough still coming out of the back of the fusebox to attach to. Otherwise you can remove the 3/8"(wrench size) bolt in the center and remove the plug from the firewall so you can get to it.

 

The Fusible link itself goes directly into the fuse box, so I will have to remove it and replace the whole thing. I am not taking any chances.

It seems that there is another Fusible link in the same fuse box, but it is much smaller, i have not been able to locate what it attaches to, because it connects to a wire that goes back into a harness that is all wrapped up.

 

That should be the link for the the ammeter.

 

Just in front of the M/C on the inner fender is the horn relay. Just below it there's a collection of wires screwed into the support it sits on. This is the main power dist block. The alt feds here as does the main Batt line. Form here there is a fusible link- 16gauge blk that then feeds the 12red main power feed to the inner fuse panel. Check the block for 12V with a volt meter, it should be hot all the time. Then probe the #12red wire after the #16 fusible link, you can make a tiny cut in it and push the meter probe into the metal, then use red electrical tape, 3 wraps to seal it. See where the Voltage stops. If it stops where it shouldn't- ie- in a wire, there's your problem.

 

This was mentioned earlier, but I didn't see your reply. The battery grounding strap connected to the frame under the battery is a source of major corrosion. My strap was still connected (barely), but the corrosion had traveled all the way up into the cable. I took the old cable with me to an auto parts store and they made me new one with heavy duty cabling/connectors inexpensive and was easy to replace.

 

Do you have a good wiring diagram? I will be willing to help walk you through areas to test over the phone if you do not have one and are getting frustrated. Be willing to (possibly) spend some time testing to find out why you have no power to your car. It is up to you to try to put an end to this and I will be willing to spend whatever time it will take to get thius corrected. I have done this several times for guys on the forum. If you want to do this , call me.

This weekend I will be doing "honey-do's", so I know I will not be in Saturday, but possibly Sunday. Either way, If you want call me and we can work out a time that is good for you.

If you choose to do this over the phone, have your tools handy. 12 volt test light, volt meter, screwdriver, sockets, etc.
"DUB"
Corvettes Etc.
4927 Wilkinson Blvd.
Charlotte NC 28208
(704) 394-5150 EST
M-F 8:30-5:00
SAT 9:00ish-4:00ish
SUN 10:00ish-2:00ish

 

First off I would like to apologize for not being on the forum lately, well since june, I am in the military and was out in the feild, with no access. Ok here is a run down of the problem again, and what I have done;

I was driving my 76 corvette, and pulled up to an intersection, as I was going throught the intersection, everything, like some one turned off a light switch, went dead. I coasted throught the intersection, and tried to restart the car, nothing. I noticed upon inspection under the hood that the pig tail that connects to the top of the Alternator, had cam loose and the red wire was broke out of the back of the plastic conector. I thought this was the problem...

So here is a list of what I have done, all from suggestions of far better electrical guys than myself:
1. Replaced the Pigtail at the alt, and tested to make sure I had connectivity
2. Tested Starter at local autozone, tested fine
3. Replaced and tested both fusible links at starter, both are good
4. Tested both pos and neg batterycables, both tested fine
5. Checked every fuse in the fuse block below stering wheel, all fuses are good
6. Tested fusible link at dist block below mater cylinder, it also tested fine.
7. Tested battery, and it as well tested fine.

I dont know a lot about electrical, and only have basic knowledge of diagonosing such things, but I will put the starter back on in the morning (06 Sep 09) and hook the battery back up, for another go at testing everything, but as of right now I still have absolutly no power to the vehicle, none the lights dont work, it won't crank, it essentially is a giant paper weight, and I am starting to get frustrated.

VR
JR

 

Do you have power at the starter solenoid , where the large battery cable connects ?

 

Call me...I will be at work today for a while.9-6-2009
"DUB" 704-394-5150 EST