My brother just got this '82 c20 and it runs fine, but my dad put the jumper cables backward and smoke started coming out of this cable where it says 91. He disconnected it right when it started to happen, but the wire melted and burned. Does anyone know what the name of that cable is or if I can change all of that? It looks like a fuse or link, but I’m not that familiar with these trucks. Anyone help, please 
@Ainsley
Thanks, this is super helpful. I’ll check the links you provided.
Darcy said:
@Ainsley
Thanks, this is super helpful. I’ll check the links you provided.
No problem. You need to eyeball the ignition switch connector pins and the connector pigtails. Imgur: The magic of the Internet. You’ll want several pieces of 14 Gauge fusible link or buy a roll from the parts store. You only need 6-inch long pieces to connect to 10 gauge wire.
@Ainsley
Got it. I’ll make sure to get those parts.
@Ainsley
The wire burned is from the starter, 14 gauge fusible link to the firewall terminal block and to the output stud on the back of the alternator. I can’t tell if you burned the other side that goes to the plug on the side of the alternator.
@Ainsley
I’ll check that area too. Thanks for pointing it out.
Second this. Connecting the jumper cables backwards has the net effect of shorting the two batteries to each other. Likely all the fusible links in the truck are bad.
Jai said:
Second this. Connecting the jumper cables backwards has the net effect of shorting the two batteries to each other. Likely all the fusible links in the truck are bad.
That makes sense. I’ll check all the fusible links.
System Diagram — 1982 Chevy Truck Blazer 2WD V8-350 5.7L VIN L 4-bbl Service Manual | Operation CHARM. This is just one of several diagrams. Likely you fried the alternator too. Reverse polarity fries the diodes and shorts them to ground. When you hook up power again, it burns the wires and the fusible links again.
@Quillan
Yikes, that sounds bad. I’ll definitely check the alternator and diodes.
Darcy said:
@Quillan
Yikes, that sounds bad. I’ll definitely check the alternator and diodes.
I will have more info Sunday morning.
It does not start now but all the lights work which is a good sign.
Brice said:
It does not start now but all the lights work which is a good sign.
That is a good sign. It means not everything is fried.
Brice said:
It does not start now but all the lights work which is a good sign.
That is a good sign. It means not everything is fried.
I’ll keep troubleshooting. Thanks for the encouragement.
Make sure to get all the fusible links and wiring checked thoroughly. Better to be safe.
Tilden said:
Make sure to get all the fusible links and wiring checked thoroughly. Better to be safe.
Absolutely. Safety first.