Here's my problem guys. Just bought this 89 F250. Turn the key, nothing. No dash lights, gauges, no radio, heater, nothing. The headlights work. I replaced the solenoid and the ignition switch. Nothing. It's like there's no battery at all. When I use the screwdriver across the contacts on the solenoid, the starter runs. I can't find any kind of fusible link in the wiring under the hood. I figure it cant be the nss because I'n not getting anything inside the cab. Not even wipers. Any ideas guys?

 

Here's the diagram which shows 7 fusible links at the same lug where the positive battery cable bolts to the starter solenoid.

 

Thank you. That definately helps.

 

Did you replace the actual ignition SWITCH or just the key tumbler? Perhaps that pot metal piece is broken that connects the actual ignition switch to the key tumbler. Just a thought.

 

I had the same thing, but had no headlights. It turned out to be the connection at the solenoid on the inner fender. Seeing as you have lights, I think you are on the right track with the fusible links.
Sorry I can't point you in the right direction.

 

I actually replaced the electrical switch. The day I replaced the switch I had pulled it back down to check the action on the switch itself. Instead of bolting it back on the column, I left it hanging. In the on position. When I came back the next day, and realized what I had done, I expected a dead battery. But the battery was fully charged. So, even though the switch was turned on, there was no battery drain. Which I guess means no juice to the switch. Which leads me to further believe I may be on the right track with the fusible links.
I'm goin back over this morning to replace those links. I'll post here what the results are.
Thanks again for the input guys. Especially that diagram F150 posted. I'd still be fumbling around in the dark without it.

 

Here's a diagram of the ignition switch. 12 volts comes from the two yellow wires which comes from the same fusible link M. The diagram is for a Gas engine. Diesel wiring schematics are different.



This pic. shows the ignition switch and how it applies 12 volts to the fuse panel.

Example: Notice when the ignition switch is in run, you should measure 12 volts on Fuse 18 and Fuse 15.

Fuse 18 is for seatbelt buzzer, warning indicators. Fuse 15 is for auxiliary fuel tank selector switch.

 

Ok, the problem isn't in the fusable links. I can't see any damaged wire anywhere. Could it be the neutral safety switch? I always thought if that nss went, you still got dash lights, radio and heater. I don't get anything except dome light, and headlights. That's it.
Anybody have any other ideas?

 

At the ignition switch you should measure 12 volts at the two yellow wires. That 12 volts comes right from the battery from the "M" fusible link.



I've circled in red the two yellow wires that must have 12 volts on them at the ignition switch.

If you have a volt meter, place the red probe on one of the yellow wires and the black probe to ground. For ground you can use the outer shell of the cigar lighter.

If you don't measure 12 volts, you have a bad fusible link or the wire is broken/open some where back to the battery positive terminal.

If you do measure 12 volts, something could be wrong with the ignition switch actuator.

Even if the neutral safety switch was bad, it would only cause the starter to not engage. It would have no effect on the circuts that you say don't work such as the radio.

 

Ok, I tracked the yellow wires in the engine compartment. The yellow wires are all hot under the hood. When I check the yellow wires under the dash, I got nothing. I can't figure out where I'm losing the juice . Is there a sensor or something I'm missing? I can't see any visible damage to anything in the engine compartment.
Anybody have any ideas? I'd appreciate any help guys.

 

maybe the wires got cut where they cross throught the fire wall... Just an idea... Maybe from rubbing on the firewall they got cut... just my 2 cents...

 

They run thru a yoke. Nothing rubs anywhere.
Those yellow hot wires that come into the cab for power, Do they run into the fuse panel and then disperse from there? Or do they run straight to the ignition switch?
I can't see up under there. But everywhere those yellow wires are visible, there's no juice.

 

Finally found the cause of my no start. I tracked the problem down to a hot wire running through the firewall. Just before the wire hooks into a yoke, I noticed a small bulge in the wire. Turns out the wire had corroded inside the insulation. The only thing in that section I cut off was a green dust.
Now I just gotta figure out why it's running rough. To the hunt!!

 

Baby step dude baby steps! good luck