KBar

Ok so i was installing my electric fan and I need a constant hot for the the thermo probe relay. So I thought why not wire it into the fuse block under the hood and when I was pushing hot the 80A fuse out one of the sides touched a bolt that holds the fuse block to the fenderwell.( I know I should have disconnected the bat first but I had a brain fart) Now I have no power to anything but my battery is ful somehow the fat white wire on the otherside of the fuse is grounded. I tested continuity with that wire and the the neg terminal and it has continuity.

The 80A fuse has 4 wires 2 whites (1 fat and 1 skinny) and 1 red/white 1 red/blue. On the wire diagram it shows that one white goes to the alt and the other goes to the efi fuse, and shows the red/blue wire going the hazard/ turn signal, and the red/white going o the ignition. The fat white wire is what has continuity with the neg terminal.
Could I have shorted out my alternator?

KBar

ok so the alternator positive and the neg terminal on battery have continuity I guess ill replace the alternator tomorrow

wyoming9

iTrader: (1)

Are you working on the 86 in your signature.

you can`t check continuity on a live circuit.

Touching any hot wire to ground will complete a circuit.

Check your fusible links and fuses to see if any are open!!

KBar

Yes 86 and the battery is disconnected all the fuses are good
Gonna takr the alt off and test it. The alt grounded out somehow

KBar

so the alt it tested bad, replaced it but I still cant get any power. My next place is the starter. I'm only getting .75 volts to the 80A fusible link

rustypigeon

.75 volts where? If you are getting this immediately after the fusible link, then the fusible link is bad.

KBar

It was before the fusible link the .75volts was from the main coming off the battery to the fuse. I found the issue it was a burnt connection in the same line. New alternator and new main power line all is good now

arlindsay1992

iTrader: (8)

The wire that comes from the battery to the fuse box is the fusible link. The definition of a fusible link is a wire that is somewhat smaller in gauge than normally used in a circuit that draws that current. It's purpose is to melt and break connection in the event of an over draw, such as a short hot to ground. It works just like a fuse, but it's not a fuse, it's a wire, or fusible link. The fuse after the fusible link is a fuse.

scope103

Sounds like KBar just replaced his fusible link with a full-sized cable. I hope he likes chatting with firemen ....

KBar

The PO replaced the main wire with a 12 gauge wire and it doesnt have fusible link. I was confusing the 80A fuse with a fusible link. I guess its back to part store to buy a fusible link. Thanks for the info damn I feel stupid

wyoming9

iTrader: (1)

If the fusible link was there good chance you would not have killed the alternator.

Good thing the wire melted or you would have had a very interesting fire.

arlindsay1992

iTrader: (8)

Don't feel stupid. Mistakes happen and you can't feel bad for not knowing everything. If nothing bad happened, then it's just a lesson learned.

scope103

You might want to look at this page https://www.yotatech.com/forums/f116...22/index9.html from Philbert's (very) long posting. According to what Philbert (and others) found, a fusible link is not an off-the-shelf part, but rather is made up from "fusible link wire" you buy in a spool. Another source suggested just using a short piece of wire known to be too small for the current, with the idea that it would just burn through on an extreme overload.

And perhaps as importantly, some parts sources refer to the 80 and 40 amp fuses as "fusible links," just confusing it with the real fusible link up near the battery.

Let us know what you find out; as I posted in Philbert's thread, this was all news to me.

KBar

I found universial fusible links at autozone

jerry507

Fusible link wire is made up of normal copper wire sized four gauges smaller than you would normally need. The "special" part is a high temperature jacket that won't melt when the link fuses. Most automotive wire is polyethylene jacket, resistant to oil, moisture, acid etc etc and decently resistant to excessive heat and abrasion. Fusible link jacket is usually more like insulation rather than a jacket.

Locating it close to the battery, as pointed out before, gives you the most protection from the only thing that can source that much current, your battery.

Note that fusible links aren't designed to protect the components in your vehicle, that's what the fuses are for. The fuses blow MUCH faster and at considerably lower currents. Fusible links prevent the wires in your car from melting, so unless you like buying replacement wiring harnesses they're a worthwhile investment.