Hey guys,

I'm brand new to the forum and am hoping to get some help on a hopefully minor issue that recently occurred on my 1986 Chevy D-30 CUCV Ex-Military truck (1.25 ton 4x4 with 6.2 diesel motor). I purchased the truck from a gov auction and the guy there said "you may luck out and just have to put some batteries in it..." So I got the thing home, slapped two batteries in (connected in series for 24 volt system) and voila! the truck started up as if it had never sat more than a day in its life without running. I let the thing run for a while, the idle dropped down once it got to temp and I drove it up and down the street a few times. This truck drove great with no hesitation and excellent shifting. So then I decided to take it out and try out the 4 wheel drive. Got it out to the hills and locked the hubs, climbed a few hills with no hiccup whatsoever. I started driving it down a really bumpy dirt road at around 25 mph or so and the thing just shut down. I smelled smoke and
popped the hood to check it out. It melted the negative post completely off of one of the batteries (the main ground) and also melted a small wire connected to the main negative lead that was connected to the radiator support. I then noticed that at the 12v junction block, one of the fusable links was destroyed, broken in half and the plastic was melted off of it. I traced this wire to the driver's side alternator. Thinking that the ground may have been a bad connection, I rewired the ground wire, spliced in a fusible link where the other one failed, and tried to re-connect the batteries. Now I am getting a huge spark when trying to connect the batteries. I am hooking up the jumper wire first, when I try to connect the ground is when I get a huge spark, so something isn't right and I can not for the life of me figure it out.

Any insight would be greatly appreciated! I was so happy when this truck started right up and ran so nicely, I want to get it back there asap!

i had nearly the same thing happen in a car. the positive wire to the starter had rubbed against the frame and it burn't the fusable links. to get that much melting and sparking, you must have a dead short. so check all your main battery cables first

i had nearly the same thing happen in a car. the positive wire to the starter had rubbed against the frame and it burn't the fusable links. to get that much melting and sparking, you must have a dead short. so check all your main battery cables first

Thanks for the reply...did you have to replace all of the fusable links? Is there a way to know if other fusable links may have blown? As you know the fuse is coated in opaque black plastic...

My first guess would also be the positive cable grounding out. You might also want to check the height of your terminal posts on your battery to see if they might be making contact with the hood, had that happen once. I have been waiting to get some extra cash together to get one of the surplus vehicles such as yours (1 1/4 ton), lots of them available at the gov autions around here.

You need to replace that broken junction block.......... (you didn't say you had yet)