Need help with neutral safety switch wiring

[PetesPonies]

Well I think I explained everything is a previous post, that no one seemed to want to acknowledge , ,so to me, it was fitting.

[Gary Lewis]

The 1981 EVTM is correct - there was no Neutral Safety Switch on the 1981 trucks.

First, here's a connectivity check between the red/light blue wire that pulls in the starter relay/solenoid and the ignition switch's connector.  And, as you can see, out on the floor with no truck and especially no transmission there's full connectivity just like the 1981 EVTM says there should be on Page 18.  And that would not be the case if there was an NSS some place that wasn't connected to the transmission.




Second, on the later trucks the connector in the wiring harness that handled the NSS also handled the backup light switch.  That connector, C128, is shown in the 1986 EVTM on Page 80 for the backup lamps and Page 30 for the start circuit.  That's an 18-pin connector.  But, the 1981 just shows a 2-pin C1016 or C1018 connector for the backup lights on Page 46.  And here's that connector on Dad's wiring harness:




I rest my case.  

[PetesPonies]

I see a jumper wire in the second pic.

[Gary Lewis]

I don't understand. A jumper wire on the backup light connector?

[PetesPonies]

Over the years, Ford has moved the reverse light switch from the column to the NSS. So sometimes there are 4 wires going down o the trans, sometimes only 2. New to Bullnoses, so . .not sure what Ford used in the beginning of this design. I think 80 to 81 had several changes. I've never encountered a vehicle with auto trans without a NSS. Hell they were used in the 1940's and '50s :) They were used 1979 and I know my '83 Bronco has one. So why they would find a reason to not use one is baffling. I did a quick search and found someone saying that in '80 the NSS was at the column.

[Gary Lewis]

That is a piece of rubber that came out of the mold when the connector was made.  Here you can see the black/pink and pink/orange hash wires for the backup light.




Here's the wiring diagram from the EVTM showing the above connector and wires:




And here's the wiring diagram for the starter wiring, which is a perfect fit for the harness off of Dad's truck.    There is no other connector for the transmission in the harness, and the starter solenoid is directly connected to the ignition switch.  So, there is no neutral start switch on a 1981 Ford light-duty truck.

[Roger Carter]

Gary,

Thank you for the pictures and information. What your recent posts show confirm what I found today as I dug deeper into the 81's wiring.
I previously checked with my local Ford dealer's parts department about a NSS for the '81. Their parts books do not show one, either.

The lack of a NSS is baffling to me. In my 50+ years of working on Fords, this is the first one I have encountered with an auto trans and no NSS.
Apparently the mechanical interlock between the key switch and shift lever serve the purpose of the NSS.

Pete, I don't want you to think I ignored any of your posts or comments. I read and acted on all of them. I apologize if I left the impression I didn't pay attention to them

And to all who responded to my pleas for help, I want to thank each of you. I hope I can return the favor.

As we used to say, in the before times, Keep on Truckin'

[Gary Lewis]

Happy to help.  And I think we got to the bottom of it.

[85lebaront2]

Just reinforces my feeling that Ford's entire engineering department must have either walked out when Lee Iaccoca left or was smoking some dynomite sheet then, especially the electrical group.

[PetesPonies]

My 42 years of working on Fords, along with the 30 or so involved with other makes, I have never seen an auto without a NSS either. I just don't follow the logic. But hey, I don't like slushboxes anyway  :)