Truck Repair: Coil 1986 Ford F150, spark plug wires, electronic engine control

Question
I'm working on a 1986 Ford F150 6 cyl I have a few different questions

The problem with the truck is it will not start it will crank & crank but wont start it is getting gas in the carb but I'm not getting any spark from the coil wire or the spark plug wires.

1)   There is 2 wires going to the coil besides the coil wire where do they go from the coil these are electrical wires?

2)   One of the coil wires got very hot & the coil started smoking & the coil got very hot do you know what would cause this?

3)    Is there a place I can go online to see a wiring diagram for the engine


Thanks a bunch
Ray


Answer
Hi Ray,
I believe you have EEC4, electronic engine control. The two wires to the coil...one is marked Batt, and the wire comes from the ignition switch, and should be 12 volts when the switch is in run or start position. If not, check for a blown fuse, or open wire. A jumper to batt + connected to that terminal will act as a "Hot wire" to test the system.
The other wire connection may be marked "Tach", and that wire goes to the electronic control system, computer, or whatever you want to call it. DuraSpark 2 maybe even. But it is what controls the spark. It goes to pin #1 of the four wire connector,,,,the green wire.
Sounds like the coil may have an internal short, because power to one wire, and grounding the other is how it makes spark. Actually the removing of the ground is what causes the spark to occurr, but that is how it works, so the heat and smoking may have been a coil problem.

I don't know where to find a diagram on line, but at the public library, in the refference section, they have manuals that you can make copies of, and they will have the diagram.

That system...EEC4, or DuraSpark, sometimes needs what Ford called a "Breakout box" to properly test the system.

Good luck,
Van