****UPDATE****Truck dies at highway speeds..(2000 F-250), wont start, HELP!
 

Hey guys i got the truck started today and I left it at idle while I was wiggling wires and such....nothing was kiling the engine until I got basically in the engine compartment. I heard a repetative ticking from the A/C but started wiggling wires from that area. There is a wiring haness that has a connection point at the A/C aluminum deal behind the battery, a connection at the batt relay on the firewall and then goes to the alternator. I wiggles a YELLOW wire (heavy guage) with a while stripe on it and the enginge died...this wire was HOT! After it died I wiggled it some more but the connection didnt seem loose and there are several other wires that moved when that one was moved. Anyone know what there could cause the engine to die, and die at intermittent times, specifically when in forward gear or at highway speeds and then make the truck NOT START at all after it dies until it sits for awhile? Im getting close, but I need some help guys!!!
Thanks,
Shawn

Where did that wire come from and go to?

Have you pulled the error codes yet?

It was in the back of the alternator and then disappeard into that harness. It branches all over the place....I dont do good with electrical sensors and such and all this computerized stuff....but I went out to see if it would happen again and i wiggled the same wire and it didnt die, but it got hot fast. I am wondering if its something to do with the temp of this wire rather than it being a lose or frayed wire.....It was too hot to deal with the second time I checked it....I will try and trace it later if there is daylight. This is going to end up costing me boku bucks because I am going to have to have it towed 20 miles to the dealer and then pay for their diagnostics at 100 upfront cost and then whatever it takes to fix the dang thing. I love my SD, but this is what frustrates me more than anything with the new trucks....My 79.....anything goes wrong its visible, the wires that are there are necessary and thats it.....all these sensors and BS have got to be some ploy by the manufacturer just to get you to spend more money to repair them because they know you dont have a clue and get stranded on the highway in BFE....they design the things to fail and its all in quest of the almighty dollar.

I dont have a check engine light on or anything.....when if first happened I turned the idnition on and off several times to do the factory reset to clear whatever....I dont know of any other way to get or clear any error codes on this truck.

I had a bad relay on my 06 F350 firewall that cut the engine off when I released the parking brake and it would slam up vibrating the firewall and causing a bad connection in that relay. Could be that firewall relay. Ford fixed it.

Now I catch the brake with my foot first cuz I'm skerred.

What engine in your SD? 5.4L, V10, or PSD?

its a V-10....

Well, we need to get back to some basics here. You're not giving us enough information to help you.

Your engine needs 4 things to run, remember the acronym FAST.

Fuel

Air

Spark

Timing

Fuel: Are you getting fuel? As was mentioned in the previous thread, get a can of starter fluid. When it dies again, spray some into the air cleaner box and try to start your truck. If it starts for a quick moment and dies you probably have a fuel delivery problem. Start looking at the fuel pump and related parts.

Air: Usually not a problem unless you are driving in real deep water or have something stuck in your air box.

Spark: Are the spark plugs firing? It ws easier to tell in the old days, you just yanked a wire off of plug and held it 1/8 of an inch away from the plug while someone cranked the engine over. (Guys who did this often usually had curly hair) A voltmeter would be better at finding out of you have spark now. If not, look at the ignition system and PCM.

Timing: Does the spark happen when it is supposed to happen? Do the valves open and close when they are supposed to open and close. A good sign that this is a problem is backfiring thru the exhaust or intake.

Also, look for other signs when the truck dies. Does everything shut down or just the engine. Does the radio have to be reprogrammed every time the engine dies? This could be a sign of an electrical or even a battery problem.

If that wire is getting hot enough to the point where he can't touch it, there is a short or break somewhere in the wire. He needs to get it fixed before he ends up with an electrical fire, which is not fun.

OK, that yellow wire is the alternator wire. It is what carries current from the alternator to the rest of the truck. It will get very hot if you have an electical problem somewhere, but that will probably not be the cause.

If the engine died when he was moving that wire the short very well could be in it. It could be in one of the other wires in the same harness too, but I'm not familiar with all the wires in that harness, anyone else.

The truck will idle fine if I dont do anything to it, then it cuts out after it has been:

1.) Idling for along time, will die and wont re-start
2.) Driven any distance (just to the stop sign, maybe 500 feet)it will die and not re-start
3.) The one time I wiggled that HOT yellow wire and heard a ticking noise form the A/C condenser (they have wires in that same harness)

I found my short because over the sound of the engine I could hear the sound of the arc made when the wire hit the frame. Could that have been the ticking sound you heard. I think you are on the right track by looking closer at that wire harness.

I gave up, I have to have the truck up and running to tow a trailer by next weekend....I strap towed it 30 miles to Milner FOrd in Harrisonville, MO.....hopefully they can narrow it all down and get it fixed for me relatively cheaply.

Those electrical gremlins are some of the hardest to trace. Hope the Dealership tracks it down for you.

Please post back...when fixed. Would love to know what it ends up being...

Good luck...

biz
8D