Fusible links issues

[Nelsonater]

Hey there, new to this forum. I have a 1982 K10 and i had accidentally hooked the battery up backwards. immediately realized what i had done do to the smoke and unhooked it. i have replaced the fusible link and it started and ran, but kept blowing it. so i figured it was my alternator and replaced that seemed all healthy turned it off and started it a few times to see, then boom it blew and fried volt, oil, temp, and fuel gauge, which i had replaced with the digital itellitronix gauges. now I'm stuck don't know where to look, i pulled my starter to get at those fusible links but figured i would get some info before i dig to deep.

 

[TravisB]

I've never done this myself so I don't have much to offer. I am going to follow along though and maybe learn something.

 

[Old77]

I moved this to a more appropriate subforum rather than "Introduction" so that it gets more appropriate visibility

 

[Charlie]

 

[75gmck25]

In my truck there are fusible links on both ends of the main power wire. There is one at the starter, and one in the wire that connects to the bottom of the junction next to the brake booster on the firewall. When I hooked up the battery backwards, it fried the fusible link at the junction on the firewall.

There is also a fusible link in the alternator charge wire where it connects to the starter.

First try a simple solution
- Leave the large battery cable connected to the starter, but disconnect the smaller power cables. Make sure you leave the purple wire connected to the solenoid.
- Run an 8 gauge wire with 12 gauge fusible link, directly from the battery positive to a new junction on the firewall (I usually get the junction from pick and pull). Then run a new alternator charge wire (8 gauge with 12 gauge fusible link) from that junction, along the valve cover and over to the BAT terminal on the alternator. Now you have 12 volts to the alternator, and a new power point with a constant 12 volts.
- For my older truck (no PW or PL) I would then run a new 10 gauge wire with 14 guage fusible link over from your new power junction to the existing junction next to the brake booster. This gives you the 12 volts constant power you need. Since your truck probably has more options, you might also want this wire to be 8 gauge with 12 gauge fusible link.

I suggest disconnecting the existing power wire that runs directly down from the junction next to the brake booster, since this may be the wire that's shorted. It runs down, around the back of the engine, then through a metal tube mounted to the engine (to protect it from the exhaust), and then to the starter. There are lots of places where there could be bare wiring that is not visible.

Once you get this wired up you will have reliable power, and will no longer be using the old wiring with fusible links. All the links will also be easier to see. Then start the rest of your troubleshooting.

Bruce