PetesPonies Posted September 19, 2017 Share Posted September 19, 2017 The wiring for the NSS located on the C6, exits the main harness near the base of the brake booster, on my 1986 F150. It travels down the left frame rail about a foot. You will see a 4 wire plug that connects to the very long pigtail of the NSS / backup light switch mounted left side of the C6. I am not sure if the C4 is in the same location. I am not completely convinced my truck will not start if I disconnect this connector. As my truck is an Auto, the column has a mechanical lockout to keep the key from rotating to the start position unless the gear selector is in Park or Neutral. This lockout means you don't need a NSS with an auto column. Jim I'm convinced . .try it. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 19, 2017 Share Posted September 19, 2017 The wiring for the NSS located on the C6, exits the main harness near the base of the brake booster, on my 1986 F150. It travels down the left frame rail about a foot. You will see a 4 wire plug that connects to the very long pigtail of the NSS / backup light switch mounted left side of the C6. I am not sure if the C4 is in the same location. I am not completely convinced my truck will not start if I disconnect this connector. As my truck is an Auto, the column has a mechanical lockout to keep the key from rotating to the start position unless the gear selector is in Park or Neutral. This lockout means you don't need a NSS with an auto column. Jim I know the early trucks, like through '81 at least, didn't have a clutch lockout switch, so it would be possible that the autos didn't have an NSS. And while I said Dad's did, I'm not sure that is correct. As Jim pointed out, if you can't turn the key it shouldn't be able to start. Link to comment Share on other sites More sharing options...
85lebaront2 Posted September 20, 2017 Share Posted September 20, 2017 I know the early trucks, like through '81 at least, didn't have a clutch lockout switch, so it would be possible that the autos didn't have an NSS. And while I said Dad's did, I'm not sure that is correct. As Jim pointed out, if you can't turn the key it shouldn't be able to start. Gary, on Darth, the NSS was on the side of the C6, between the shift lever and the downshift lever. Older models with the FMX had it on the column as there was no place on an FMX, Castr Iron Cruise-O-Matic or Ford-O-Matic for one, C4s used essentially the same switch, the AOD has a plunger switch in the case. Yes, the key mechanism is mechanically interlocked, but the NSS also controls the back up lights, and shifters can get out of adjustment. FWIW, I had a good friend that was killed by his wife's Explorer he was working on for his granddaughter. He thought the NSS was bad and was underneath jumping the starter, switch was good, Explorer was in reverse and backed of the ramps crushing his chest when he tried to roll out from under it as it started moving. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 20, 2017 Share Posted September 20, 2017 Gary, on Darth, the NSS was on the side of the C6, between the shift lever and the downshift lever. Older models with the FMX had it on the column as there was no place on an FMX, Castr Iron Cruise-O-Matic or Ford-O-Matic for one, C4s used essentially the same switch, the AOD has a plunger switch in the case. Yes, the key mechanism is mechanically interlocked, but the NSS also controls the back up lights, and shifters can get out of adjustment. FWIW, I had a good friend that was killed by his wife's Explorer he was working on for his granddaughter. He thought the NSS was bad and was underneath jumping the starter, switch was good, Explorer was in reverse and backed of the ramps crushing his chest when he tried to roll out from under it as it started moving. Yep, that's where the switch was on Dad's C6, but now I'm wondering if the truck only used the backup light portion thereof. Man, that's awful about your friend. My father taught me a healthy respect for vehicles being lifted off the ground, so I am extremely careful. But after seeing that maybe I need to step it up another notch. 🙈 Link to comment Share on other sites More sharing options...
PetesPonies Posted September 20, 2017 Share Posted September 20, 2017 I know the early trucks, like through '81 at least, didn't have a clutch lockout switch, so it would be possible that the autos didn't have an NSS. And while I said Dad's did, I'm not sure that is correct. As Jim pointed out, if you can't turn the key it shouldn't be able to start. Autos have had a NSS since there were automatic transmissions. True, clutches didn't have switches . . . but we dumbed it down for the masses :) I have still, many cars/trucks with no switch on the clutch. I always started a vehicle my depressing the clutch, same with motorcycles. CSS is just another thing to go bad, IMO. But hey, it's been around for a while, I remember when it started. Link to comment Share on other sites More sharing options...
Roger Carter Posted September 20, 2017 Author Share Posted September 20, 2017 Autos have had a NSS since there were automatic transmissions. True, clutches didn't have switches . . . but we dumbed it down for the masses :) I have still, many cars/trucks with no switch on the clutch. I always started a vehicle my depressing the clutch, same with motorcycles. CSS is just another thing to go bad, IMO. But hey, it's been around for a while, I remember when it started. Hello All, First, a thank you to everyone who has posted a comment. I appreciate the help. I had a chance today to get back to the truck in question. I thoroughly checked the underside for plugs, connectors, wiring tails, etc. Found one plug and connector near the cross member, it was a factory 2 wire plug and connector, and from the colors it appeared to be the back-up light wiring. These wires were in their own loom, with no other wires. Tracing the wires rearward, they went to the back of the truck. No bed or lights on the rig yet. Going forward, this loom ran into a piece of convoluted wire loom with one other wire loom. Tracing this second loom to the rear, it had the sending unit wire for the fuel tank and carried on to the back of the truck with tail and turn signal wiring. There were no other plugs, connectors or wire looms tucked inside (or outside) the driver side frame rail. I didn't have a chance to follow the convoluted loom into, or to do any digging for wires in, the engine compartment. Hopefully that can be a chore for tomorrow. Previously I had done some looking, but had seen nothing with the correct colored wires. Will need to dig deeper. As for attempting to start the rig, that is a couple days away. I don't have an issue with starting it without a NSS, but do want to avoid any catastrophic accidents. I want to be certain the truck is safe when I return it to its owner. There does seem to a mechanical interlock between the key switch and the shift lever, with the key being able to be removed only when the shifter is in the PARK position. I doubt this would be used in place of a NSS, but will have to do further checking. The trans in the truck is a C4 from a early 70's Mustang, and the NSS is the same, or very similar to those on a C6, as described by previous posters. The switch is a combination NSS and back up light switch, with four wires coming from it. Beginning to think the '81 EVTM was correct in not showing a NSS in their diagrams... Thanks again for all the comments, hints and suggestions. I will post my findings as I dig deeper. Link to comment Share on other sites More sharing options...
ctubutis Posted September 21, 2017 Share Posted September 21, 2017 Hello All, First, a thank you to everyone who has posted a comment. I appreciate the help. I had a chance today to get back to the truck in question. I thoroughly checked the underside for plugs, connectors, wiring tails, etc. Found one plug and connector near the cross member, it was a factory 2 wire plug and connector, and from the colors it appeared to be the back-up light wiring. These wires were in their own loom, with no other wires. Tracing the wires rearward, they went to the back of the truck. No bed or lights on the rig yet. Going forward, this loom ran into a piece of convoluted wire loom with one other wire loom. Tracing this second loom to the rear, it had the sending unit wire for the fuel tank and carried on to the back of the truck with tail and turn signal wiring. There were no other plugs, connectors or wire looms tucked inside (or outside) the driver side frame rail. I didn't have a chance to follow the convoluted loom into, or to do any digging for wires in, the engine compartment. Hopefully that can be a chore for tomorrow. Previously I had done some looking, but had seen nothing with the correct colored wires. Will need to dig deeper. As for attempting to start the rig, that is a couple days away. I don't have an issue with starting it without a NSS, but do want to avoid any catastrophic accidents. I want to be certain the truck is safe when I return it to its owner. There does seem to a mechanical interlock between the key switch and the shift lever, with the key being able to be removed only when the shifter is in the PARK position. I doubt this would be used in place of a NSS, but will have to do further checking. The trans in the truck is a C4 from a early 70's Mustang, and the NSS is the same, or very similar to those on a C6, as described by previous posters. The switch is a combination NSS and back up light switch, with four wires coming from it. Beginning to think the '81 EVTM was correct in not showing a NSS in their diagrams... Thanks again for all the comments, hints and suggestions. I will post my findings as I dig deeper. Roger, I think you just answered your own question... There's an interlock in the column that disallows turning the key to START when equipped with an automatic transmission and the selector lever isn't in PARK or NEUTRAL, this should eliminate the need for a NSS, no? 1981 manual-trans trucks don't have a clutch switch so it wouldn't surprise me if there aren't provisions for a trans-lever switch (seeing as how there's a mechanical block that does the same thing). The backup lamp wiring is black/pink IIRC. Link to comment Share on other sites More sharing options...
PetesPonies Posted September 21, 2017 Share Posted September 21, 2017 Roger, I think you just answered your own question... There's an interlock in the column that disallows turning the key to START when equipped with an automatic transmission and the selector lever isn't in PARK or NEUTRAL, this should eliminate the need for a NSS, no? 1981 manual-trans trucks don't have a clutch switch so it wouldn't surprise me if there aren't provisions for a trans-lever switch (seeing as how there's a mechanical block that does the same thing). The backup lamp wiring is black/pink IIRC. wow . . . . he he OK if you think that. Link to comment Share on other sites More sharing options...
ctubutis Posted September 21, 2017 Share Posted September 21, 2017 wow . . . . he he OK if you think that. well that's a friendly, helpful response Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 21, 2017 Share Posted September 21, 2017 Hello All, First, a thank you to everyone who has posted a comment. I appreciate the help. I had a chance today to get back to the truck in question. I thoroughly checked the underside for plugs, connectors, wiring tails, etc. Found one plug and connector near the cross member, it was a factory 2 wire plug and connector, and from the colors it appeared to be the back-up light wiring. These wires were in their own loom, with no other wires. Tracing the wires rearward, they went to the back of the truck. No bed or lights on the rig yet. Going forward, this loom ran into a piece of convoluted wire loom with one other wire loom. Tracing this second loom to the rear, it had the sending unit wire for the fuel tank and carried on to the back of the truck with tail and turn signal wiring. There were no other plugs, connectors or wire looms tucked inside (or outside) the driver side frame rail. I didn't have a chance to follow the convoluted loom into, or to do any digging for wires in, the engine compartment. Hopefully that can be a chore for tomorrow. Previously I had done some looking, but had seen nothing with the correct colored wires. Will need to dig deeper. As for attempting to start the rig, that is a couple days away. I don't have an issue with starting it without a NSS, but do want to avoid any catastrophic accidents. I want to be certain the truck is safe when I return it to its owner. There does seem to a mechanical interlock between the key switch and the shift lever, with the key being able to be removed only when the shifter is in the PARK position. I doubt this would be used in place of a NSS, but will have to do further checking. The trans in the truck is a C4 from a early 70's Mustang, and the NSS is the same, or very similar to those on a C6, as described by previous posters. The switch is a combination NSS and back up light switch, with four wires coming from it. Beginning to think the '81 EVTM was correct in not showing a NSS in their diagrams... Thanks again for all the comments, hints and suggestions. I will post my findings as I dig deeper. Roger - I'll pull the harness for Dad's truck out tomorrow and see if it has the NSS connector. I'm thinking like you that the 81's didn't have it and the EVTM is right. But I'll find out. Link to comment Share on other sites More sharing options...
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