Ok, will do my best to walk you thru the problem....
Assuming your truck has a manual transmission (because I am to lazy to go look), there is a black w/yellow wire that runs down the steering column to a switch on the clutch pedal under the dash - this switch prevents the truck from starting unless the clutch is pushed in.
from the switch, there is a Black w/green wire that goes thru the firewall all the way to the small terminal on the starter motor. This series of wires carries a 12+ signal.
Now for the ignition side of life... from the ignition switch there is a small Black w/white wire that runs down the steerin column thru the firewall and out to the ignition coil, positive terminal. When the ignition switch is turned on you should have a 12+ signal all the way to the coil.
If your truck ran before, the rest of the woring should be intact.
Hope this helps. Don't know if the drawing will help or not but figured I would include it.