209trucker

Hello all, Last Saturday morning on my way to work, I noticed a heavy voltage drop, followed by my radio cutting out when driving under roughly 45 mph. So, I came home and tested my alternator, putting out around 8.8-9 volts, and deductive reasoning lead me to buying a new one. Put it in, ran the truck, radio and lights were still cutting out. So, I disconnected the battery terminals and let it charge for a couple hours. When I hooked the battery back up, POOF, smoke arises from the wire loom on my passenger side inner fender. Looked like a previous owner had seen a problem, and addressed it with some electrical tape. I crimped a new ring terminal on first to be sure that was my problem... I was getting an arc from my battery, then another POOF, and the green 10ga fuse link wire goes up in smoke. Awesome! If any of you remember, a few months ago I had a wire issue, and the solution was to buy a 150amp AMG fuse and some bigger wire, I had bought what I need, but due to the constant need of my truck I never made the time to do it, now I regret it. Anywho, I run my new wire and before I decide to put my fuse in, I wanted to see if there was still a current draw, I did not see one. But the thing is now, I have NO power anywhere. No lights, no door buzzer, no ignition, nada. I do not have my alternator positive wire hooked to the terminal at the moment. I just don't know where to go with it from here. After reading NE frmhnd's thread, I feel like doing the same thing.

Angry Johnny

Sounds like you may have let the smoke out of another fuse link. Check the links at the drivers side inner fender. Sometimes they will melt inside but outside they may look OK. Pull on them and if they stretch, they are bad.

I used to repair fuse links on these trucks when they were near new so it's nothing new but as they age oxidation and decay takes it toll.

BearKiller

Okay, that big green fuse-link continues the circuit of that big black wire around to the charge-stud on the alternator.

Connected in that flat black "duck-foot" looking thing where the green fuse-link came from are several smaller fuse-links.

If that big green one melted, then most likely some, if not all, of the others went out as well.

You need to read bigragu's thread here, as the information given is a good place to start in fixing your situation.

https://www.dieseltruckresource.com/...k-t319370.html

Once you get a remote HOT stud installed, separate each wire from that "duck-foot" , cut away and discard the fuse-link, splice on a new length of same or bigger AWG wire, fuse it --- either at a fuse-block like the Del City one linked to in that thread or with a simple inline fuse --- of amperage suitable for the size of the factory wire, and thus and so forth until all of the wires in that "duck-foot" have been relocated.

Do that and things should return to working.

If not, then we will cross that creek when we get there.

209trucker

That's what I was looking for. I had a feeling that since the alternator wire was being eliminated from the ducks foot, that I would have other issues. I've been reading other threads on the fuse links, so I'll get a plan going and update as necessary.

Thanks a ton guys!

NJTman

Fusable links Stink !


Or at least that's what this guy said...

https://www.dieseltruckresource.com/...k-t317257.html

j_martin

Of course they stink.......when they blow.

The original problem is a short in the alternator, or in the heavy wire going to the alternator.

On that other thread I posted a diagram of the duck foot and amperages. Maxi-fuses the right size will work just fine. The alternator needs a 150 amp fuse, which would be one of the bolt in ones, unless yer Jim Lane, then you need 200 amps or better.

Lest you get all down in the mouth about this, the little bit of smoke from the duck foot mess probably saved a major fire burning your truck to the ground.

BearKiller

Although I just abhor fuse-links in general, the reason the Dodge-style fuse-links are so hated is more to do with how Chrysler employed them so closely molded into that duck-foot that they are nigh un-repairable without completely cutting out the entire duck-foot and starting over.

The fuse-links immediately begin where they exit the duck-foot and end exactly where all the wires disappear into the factory-wrapped "harness", with no slack whatsoever for road-side trouble-shooting or repairs.

The factory fuse-links that were on my 1985 F-350, way back in olden times, were individually ring-terminaled onto the HOT side stud of the fender-mounted starter-relay/solenoid. with plenty of slack and extra wire length; a far better system than that used by Dodge.

209trucker

Hey guys, a little update.

While waiting for some other stuff to come in, I ran my wire to the alternator with a 150 amp AMG fuse, and shrinked and taped the end of the 10ga fuse link wire, then hooked the main power to the ducks foot back to the battery. Everything's good to go for now, and when I have everything I'm going to replace all of the fuse links with fuses.

One thing though, my grid heaters aren't turning off. I noticed the wires to the battery were getting hot, and apparently the draw was so large my alternator was only giving up around 12.5 volts. I disconnected the heaters and now it's putting out 13.9-14 volts. I will have to go through the wiring, I had just replaced both relays to them maybe 6 or 7 months ago.

BearKiller

When you dis-connected the grid-heaters, did you dis-connect the two fat black grid-heater wires at the battery ??

There should also be a much smaller signal/trigger wire connected to the grid-heater solenoids; remove that wire and check it for voltage, first with key=OFF, then with key=ON.

If that trigger wire is remaining constantly HOT after the heaters should have timed out, then you may have a stuck timer.

I am uncertain just where or what type timer they have, as the first improvement I do to all of our trucks is to dis-connect the heaters and leave them so.

j_martin

Alternator delivers 120 amps. Grid heaters draw a little over 200 amps. Do the math.

This is the sort of thing that makes diagnosing a problem over the internet so difficult. There are often symptoms that the OP doesn't notice or think are important that in fact are the main clue.

NE frmhnd

I started peeling back the tape and stuff on my wiring harness tonight, after taking the battery out so I could get to it. I hope the wiring is good inside, because it'll probably still be sitting right there a year from now, while I get the underhood sorted out and replaced.