Some back story that might help.
I've been a happy owner of a 1999 F-150 since 2003, I drive a company vehicle so my truck sits in my parking lot all week, I've put maybe 400 miles on it in the past year.
I live in MA, planned a trip to visit friends in NY so I wanted to make sure the truck was in good shape for the trip. Changed the oil, the trans fluid was black, changed that, then I had to get an inspection. That's when it all started, my ball joints were about to fall off, so I had the uppers and lowers replaced.
Went to and from NY last weekend just fine, even through a snow storm. This weekend I had to drive about 30 miles to my in-laws and I came to a traffic light and it started running real rough, left it at the in-laws over night picked it up this morning and the service engine light was on. I've had a misfire before, I had to change the plugs and wires when I first got it so I figured that's what it was. But once I got back home I took a peek under the hood.





sigh... here's the kicker, I got 1 more payment left on her. Figures.
My question is what could have caused this, and what am I looking at in terms of what I'm in for to fix it, and can I feasibly do it myself, there's a lot of meltage going on there.

 

WoW that looks nasty!

 

I would be only guessing on what caused that meltdown but if you have some tools and mechanical ability, you should be able to do the work yourself. It's obvious that you need a new coil pack and some new plug wires.
By the way, excellent pic's. Because of the quality of your pic's, I can see that there is a factory wiring harness that has a melted plug connector. I would try and hit up your local bone-yard for the wire harness & connector and re-wire it. If your lucky and find that same year you should be able to match up the wiring with the same wiring color code. (ex. gr w/red stripe. or orange w/green stripe, you get the idea)
Disconnect the battery before doing any of the repair work. Follow back the factory wiring harness('s) and check to see if there is more damage than just at the end where it connects to the coil.
I have the 5.4L engine so I don't have coil paks but I have worked on vehicles that use them. Hopefully someone that has coil packs will chime in on this problem and give you more insight. I wouldn't hesitate to fix it, if it were my vehicle, or family & friends vehicles. There isn't a whole lot involved in changing out the parts. The wiring will be a pain, but time, patience and the right tools will fix that.

Good Luck with it.

TJKinCNY

 

By the way, what a crappy way for joining this site. At least when you bring a problem (melted mess) you came prepared. Thankfully you posted excellent pic's. Well done.
Welcome to the Forum.

 

Pun intended?

You can try Ebay as well. I found a new 4six harness there. A take off from a crate motor I used for parts.

 

Thanks, also for the helpful reply. Tell me about it, I've actually been reading this forum for a while. I fixed my odometer problem with Greg's sticky a couple years back, just never bothered to register. I'll have to make up for this when she's fixed and washed.

I'm pretty confident I can fix it, my fear is it happening again, the only logical speculation I have at this point is that some moisture from the storm I drove through got into the wires somewhere possibly due to it just sitting in a parking lot and the wires cracked...
I didn't think to follow those wires back to check for more damage either so i'll have my head in my Chilton's for the rest of the night.

I'm just happy his didn't happen when I was still in NY

 

You will also need a new Radio Noise Capacitor. Make sure that the new coil pack is properly mounted. The ground on the Capacitor is important.

What is that piece that is to the left of the connector in the second picture? It looks like it is under the Radio Noise Capacitor bolt and under the Plug wire boot. Red Arrow

 

wow that is a melted mess werid. have you ever changed the coil packs before this happend or are those stock?

Also JMC what does the Radio Noise Capacitor do?

 

When the PCM opens the circuit to the coils to fire the plugs it can create spikes in the current flow which causes static noise in the radio. The capacitor evens out these spikes. At least that is what I was lead to believe.

Regards

Jean Marc Chartier

 

Yeah those are stock coil packs, Only things I've done to the engine was plugs and wires when I first got it, and put an Airhog filter in.

Not sure just looks like a bracket of some sort, here's another angle.

 

humm looks like you shoulda swaped the coil packs out too when you did plugs n wires. still confuzed on how this happend. ive had my coil packs coverd in mud/water/snow and they never did this. just glad it didnt set your truck on fire.

 

Never seen that before. Shifty 85's right---lucky the thing didn't catch fire. No fuses/fusible links blew?

 

ewww nasty. looks like high resistance failure. ive got some new wires and a stock coil pack if ur interested. they're just taking up space