Electrical/starting/running issues

[TwoToneHauler]

I have a 78 Supercab with a 460.
I have replaced most of the electronics under the hood trying to figure out why it won't run without running a jump wire from the positive post on the battery, to the positive post on the coil.
I just put in a new ignition switch on it this morning, and the damn thing still won't run without the jump wire ! ! !
Has brand new: Battery, coil, voltage regulator, starter solenoid, Elec Control Module, and ignition switch.
The truck runs and drives fine, but the minute I disconnect that jump wire, it dies.
The truck turns over and runs fine, but only with the jump wire.
Any suggestions?
I'm tired of buying new parts and the thing still won't run ! !
Thanks,
Michael

 

[m78]

Look in these manuals that Duncan provided to see if you can find the problem.
http://www.fordtruckfanatics.com/fo...1&pp=20&sort=lastpost&order=desc&daysprune=-1

 

[tjcustomranger]

Check all your wiring. I had two broken wires on my truck and have it super weak spark as soon as I fixes them my spark got a lot better

 

[Fellro]

If it is fixed as simply as running a jumper, then most likely you have a wiring problem. You need to be sure that the power is actually getting all the way to the coil, which quite apparently it is not. The wires can break internally and not show the failure to you. Use a test light and work backwards through the harness until you find power. Obviously you don't want to do a lot of places, so check at every connector to isolate the trouble area.

 

[Mil1ion]

Get the multimeter out and do a continuity test of the ignition resistance wire.
Attach one end at ignition switch. .the other at the coil end
The pink resistance wire ( taped within the 14401 wiring harness)
The resistance part of the wiring is about 42" long.
Ford coils run on 5.4 - 8.2 volts ..using a 12 volt power supply will burn the coil out if used for an extended amount of time.


The ignition wire changes colours on both sides of the resistance wire.
IIRC the wire is green with red stripe.

I have photos if need be.

 

[DNFXDLI]

Look in these manuals that Duncan provided to see if you can find the problem.
http://www.fordtruckfanatics.com/fo...1&pp=20&sort=lastpost&order=desc&daysprune=-1

Thanks Mark....this one particular manual does a pretty good job of troubleshooting:

http://www.fordtruckfanatics.com/forum/showthread.php?t=29167