Need some help with an '87 F150

[sargentrs]

Not a bump but I respect you guys more than I do other sites. My DD is an '87 F150 XLT Lariat with a 5.0 EFI and C6 tranny. Had her for about 3 years. Stopped at a store a few days ago and when I came back out she wouldn't start. No power to the starter/ignition system. Tried jumping her off but no good. Had her towed home and started troubleshooting. All the lights, radio, power windows, etc are working. Battery reads 12.5+v When I turn the key to start, battery drops to 9.7v. Pulled the starter and the battery and had them load tested. Both came out good. I can jump across the solenoid, ignition terminal to starter cable with key on and she cranks right up. I have no power to the wire connected to the ignition terminal. None of the fuses appear to be connected to that circuit, all accessory/lighting type circuits which work so none of the fuses are bad. I'm thinking it's gotta be either the ignition switch, the NSS, or somewhere in between. Replaced the NSS a few months ago but I guess it could've gone bad. The wiring harness on this truck is a huge mass of multiple wires, connectors, loom, sensors, ECM, etc. I don't want to dig into that any more than absolutely necessary. The only wiring diagrams I can find on the web are pretty intense. Seems that the Red/Lt blue wire is the circuit all the way from the ignition switch through the NSS and to the starter relay. What's the plan of attack? How to bypass the neutral safety switch, test the ignition switch, narrow down where the issue may be. Any and all input is greatly appreciated.

I have her hot wired to a momentary push button switch on the dashboard but want to get it fixed right. All the new cars these days brag about the push to start function. Shoot! I got that on an '87!

[sargentrs]

I mean like, seriously!?, WTH is this supposed to mean? 5 start positions on the ignition switch diagram? Left end is for manual trans, right side is for diesel, 2 are other options but which circuit is mine? I miss my bump!

[tsherry]

Here's a weird thing to maybe look at. This happened on my old '95 F150 extended cab 4x.

There is a diode under the hood in the power distribution box. That cooked off once for no apparent reason when my son had it and it wouldn't start. Replaced that with a junkyard replacement and all was well from that point on. It looks like one of the larger 'megafuses', and mine was grey.

https://duckduckgo.com/?q=ford+truck+di ... apot-2.jpg

Shows a later module with several diodes. I think the one that I had that died was the PCM diode.

One other thing, have you replaced the ignition switch itself? before buying store bought stuff, I might replace the NSS with a junkyard part, and maybe the ignition switch too just to see...

[sargentrs]

Thanks for the advice! '87 doesn't have a power distribution box. Just 18 fuse slots under the dash, some don't apply to my truck. All are accessory fuses. Haven't replaced the ignition switch yet. Was hoping to diagnose a little further before throwing more money at it. Already wasted money replacing the starter relay unnecessarily. Darn thing was $30.

[1970FordTK]

Can't tell if that's a tilt wheel or not. But this video is what I had to do from my 89 Bronco to get it back to normal. https://www.youtube.com/watch?v=uai91X-IgeE A quick way to check it is to take the cover off of the steering shaft right where it meets the dash it will expose the long linkage rod to the starter link. A pair of vice grips on it to make it go forward will see if that will put power to the starter.

[sargentrs]

Thanks for the tp! No tilt but I was wondering how to see if that rod was working.

[1970FordTK]

Reason I know on that its how I help a friend of mine with a 90 model that his gave out while parked right in front of the post office in a no parking zone. Those two screws are about as long as your little finger and with a manual screwdriver feel twice as long to get out. Put the vice grips on the rod and made sure the key was in the on position pushed it forward and bingo truck running and out of the way. Down side, had to help replace that actuator, parts cheep, but digging out that stuff out of the column takes time and patients.

[DuckRyder]

Does it have a fusible link in that wire by chance? if it hasn't already been replace it probably has a little yellow tab made onto it.

For clarity sake, it won't spin? That is what I understand?

Try N vs Park?

[sargentrs]

Reason I know on that its how I help a friend of mine with a 90 model that his gave out while parked right in front of the post office in a no parking zone. Those two screws are about as long as your little finger and with a manual screwdriver feel twice as long to get out. Put the vice grips on the rod and made sure the key was in the on position pushed it forward and bingo truck running and out of the way. Down side, had to help replace that actuator, parts cheep, but digging out that stuff out of the column takes time and patients.

Thanks! That'll be on the list. First off I'd like to narrow it down a bit more. I want to check where the fault is. Is it between the ignition switch and the NSS or between the NSS and the starter relay. Trying first to figure out where/how to check those circuits.

[sargentrs]

Does it have a fusible link in that wire by chance? if it hasn't already been replace it probably has a little yellow tab made onto it.

For clarity sake, it won't spin? That is what I understand?

Try N vs Park?

I'm not sure about a fusible link. That wire disappears into a wrapped/loomed harness a few inches from the connector. If there is a fusible link it's somewhere in that harness further along the circuit. When I turn the key to Run all lights, accessories, etc, works as it should. Power is obviously getting to the ignition switch. Turn it to Start and nothing happens. Key feels the same as always but power is obviously not making it from the ignition switch to the starter relay. Tried Park, Neutral and holding up on the shift lever, wiggling, holding pressure around P and N, nothing worked. The NSS gave out a few months ago and it started in neutral so I just drove it like for awhile. Finally replaced the NSS and it went back to starting in P. Been fine for 2-3 months until this episode last week. Need to figure out which wire/terminal is power into the NSS and which is out or jump around it. Then I can eliminate or confirm the NSS. A good wiring diagram would help. If course this happens when winter sets in. No good comfy place to work on it. Might just have to wait till spring.