Neutral safety switch HELP!!!
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Neutral safety switch HELP!!!
Hello all,
I'm a newbie at this so bare with me. I recently bought my 77 f100. It's AT 302 2WD. Seemingly it has a newer transmission and steering column.
NSS is on trans with a square 4 prong connector just hanging unplugged in engine bay. The steering column is out of a 78-79 model so it doesn't have NSS connection on column. I have back up lights but truck starts in ANY GEAR.
Trying to figure out how to wire nss
Help
I'm a newbie at this so bare with me. I recently bought my 77 f100. It's AT 302 2WD. Seemingly it has a newer transmission and steering column.
NSS is on trans with a square 4 prong connector just hanging unplugged in engine bay. The steering column is out of a 78-79 model so it doesn't have NSS connection on column. I have back up lights but truck starts in ANY GEAR.
Trying to figure out how to wire nss
Help
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
The '77 originally had the NSS on the steering column under the dash.
It sounds like someone has already "hacked" the NSS harness because you have back-up lights.
Look under the dash for a flat four wire connector similar to a trailer connector, this may have been cut up by a PO but look anyway.
Two of the wires are the back-up lights and two are for the neutral start switch. If you find this, you'll need to splice the wires and connect them to the switch on the side of the trans.
This is what the plug will look like.
It sounds like someone has already "hacked" the NSS harness because you have back-up lights.
Look under the dash for a flat four wire connector similar to a trailer connector, this may have been cut up by a PO but look anyway.
Two of the wires are the back-up lights and two are for the neutral start switch. If you find this, you'll need to splice the wires and connect them to the switch on the side of the trans.
This is what the plug will look like.
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Joined: Mar 2006
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From: B.C. Canada
mikeo0o0o0, from what the OP said, he has the newer column without the switch, and the original transmission, also without a switch. So unless he can retrofit a switch on the tranny or the column, he's out of luck with what he has. I checked a column I have and tough to get a switch on it, although anything is possible. Not sure if the switch would fit on an older tranny.
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Joined: Mar 2006
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From: B.C. Canada
OOPS!
Oops, just read his post again and he says he has the newer tranny, so might have the switch on it.
He has the 4 wire plug apparently, so if the tranny has the switch, he should be able to just plug it in, although I don't know why he'd have back-ups.
He has the 4 wire plug apparently, so if the tranny has the switch, he should be able to just plug it in, although I don't know why he'd have back-ups.
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Well I'll just BE!!! THANK YOU SOO MUCH! I've been baffled over this darn thing for almost a year. Up until I joined this site I've been looking for that half plug in the engine bay since the plug from the transmission is hanging there.
Just went out there at MIDNIGHT recalling seeing a flat wide connection after removing cluster and wondering what it went to.
Both ends of what you sent are connected which is why I could never find the half plug.
That being said I'm assuming a PO jumped wires somewhere. Looks like my challenge now is figuring out wiring which should be attainable since they're both 4-wire connections.
LOVE THIS SITE. Just figuring this alone has answered a year of headache
Thanks
Just went out there at MIDNIGHT recalling seeing a flat wide connection after removing cluster and wondering what it went to.
Both ends of what you sent are connected which is why I could never find the half plug.
That being said I'm assuming a PO jumped wires somewhere. Looks like my challenge now is figuring out wiring which should be attainable since they're both 4-wire connections.
LOVE THIS SITE. Just figuring this alone has answered a year of headache
Thanks
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Now that I think about it, this may explain another issue I'm having. Fuse marked backup has been blowing since I've had truck. PO had jumped fuse circuit by wrapping glass fuse with foil. Since I removed it fuse blows constantly and leaves me with no turn signals or emergency flashers.
Question is where are my backup lights wired from since nss is NOT hooked up and original NSS wiring is apparently bypassed.
Sum it up PO was evidently a hack job magician. I have backup lights, no nss, and backup fuse that constantly blows leaving with no turn signals or flashers. My first assumption was a bad turn signal switch.
So obviously turn signal switch is tied to backup fuse circuit but now I'm thinking fuse keeps blowing because of the bypassed original NSS wiring somehow.
Thoughts?
Question is where are my backup lights wired from since nss is NOT hooked up and original NSS wiring is apparently bypassed.
Sum it up PO was evidently a hack job magician. I have backup lights, no nss, and backup fuse that constantly blows leaving with no turn signals or flashers. My first assumption was a bad turn signal switch.
So obviously turn signal switch is tied to backup fuse circuit but now I'm thinking fuse keeps blowing because of the bypassed original NSS wiring somehow.
Thoughts?
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Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 785
From: Simi Valley, CA
1967/77 F100/350: Same NSS located on steering column.
C7TZ-7A247-A .. NSS (Motorcraft SW-600) / Obsolete
------------------------------------------------------
1978/79 F100/350: NSS located on transmission, C6 different NSS than C4.
D8TZ-7A247-A .. C6 NSS (Motorcraft SW-1889) / Obsolete
1978/79 F100/350 & Bronco.
---------------------------
D8TZ-7A247-B .. C4 NSS (Motorcraft SW-1891) / Obsolete
1978/79 F100/150 300/302.
---------------------------
1978 was the first year that FoMoCo offered 300/302's w/a C6, but some F100/150's still came w/C4's.
Be aware that 1978/79 C6 2WD (D8TZ-7A256-A) & C4 (D8TZ-7A256-C) Manual Control Selector Levers located on left side of trans case are different than 1973/77. Both are obsolete.
btw: Why do people swap 1978/79 steering columns into earlier trucks? The usual reason: Tilt wheel introduced in 1978, operates by pressing the T/S handle forward.
C7TZ-7A247-A .. NSS (Motorcraft SW-600) / Obsolete
------------------------------------------------------
1978/79 F100/350: NSS located on transmission, C6 different NSS than C4.
D8TZ-7A247-A .. C6 NSS (Motorcraft SW-1889) / Obsolete
1978/79 F100/350 & Bronco.
---------------------------
D8TZ-7A247-B .. C4 NSS (Motorcraft SW-1891) / Obsolete
1978/79 F100/150 300/302.
---------------------------
1978 was the first year that FoMoCo offered 300/302's w/a C6, but some F100/150's still came w/C4's.
Be aware that 1978/79 C6 2WD (D8TZ-7A256-A) & C4 (D8TZ-7A256-C) Manual Control Selector Levers located on left side of trans case are different than 1973/77. Both are obsolete.
btw: Why do people swap 1978/79 steering columns into earlier trucks? The usual reason: Tilt wheel introduced in 1978, operates by pressing the T/S handle forward.
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Joined: Apr 2012
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From: Spencer Mountain, NC
Do your backup lights only come on when the transmission is placed in reverse? Do they only come on when the headlights are on? Are they on all the time the truck is running? The answer to these questions will make chasing down your problem easier.
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
Well I'll just BE!!! THANK YOU SOO MUCH! I've been baffled over this darn thing for almost a year. Up until I joined this site I've been looking for that half plug in the engine bay since the plug from the transmission is hanging there.
Just went out there at MIDNIGHT recalling seeing a flat wide connection after removing cluster and wondering what it went to.
Both ends of what you sent are connected which is why I could never find the half plug.
That being said I'm assuming a PO jumped wires somewhere. Looks like my challenge now is figuring out wiring which should be attainable since they're both 4-wire connections.
LOVE THIS SITE. Just figuring this alone has answered a year of headache
Thanks
Just went out there at MIDNIGHT recalling seeing a flat wide connection after removing cluster and wondering what it went to.
Both ends of what you sent are connected which is why I could never find the half plug.
That being said I'm assuming a PO jumped wires somewhere. Looks like my challenge now is figuring out wiring which should be attainable since they're both 4-wire connections.
LOVE THIS SITE. Just figuring this alone has answered a year of headache
Thanks
I learned a long time ago that the worst possible thing that can happen to one of our trucks is a "previous owner".
Yes, now you'll have to play detective and start searching for where the PO butchered the electrical system.
What you will eventually need to do is extend the wiring from the plug under the dash to the plug that's on the side of the tranny.
It also sounds like you have a short to trace down. Although this could be caused by something else, my first suspicion would be the PO hack job.
I don't know how good you are at reading technical drawings but you can go here: 1973-1979 Ford Truck Wiring Diagrams & Schematics - FORDification.net for copies of the FACTORY wiring diagrams. They don't have the '77 yet, but for this you can use the '76. The NSS wiring is the same. Same deal with the 78-79. They haven't finished the '78 but you can use the '79.
It should be fairly simple to extend the wiring. If you could find an early (67-77) switch, you could cut the plug off the switch and use that as a start for your harness extension.
Good luck.
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MikeoOoOoO,
Getting somewhat familiar with reading the techs. Found another hanging plug in engine bay that looks like a back up switch plug. Still a wild card but thinking this may be cause for fuse blowout because there is no jumper on it.
I'm confused as to where a backup light switch would be if nss WAS also backup switch or is it likely truck was at one time manual?
Enjoying the journey but this thing is wearin me out!
Getting somewhat familiar with reading the techs. Found another hanging plug in engine bay that looks like a back up switch plug. Still a wild card but thinking this may be cause for fuse blowout because there is no jumper on it.
I'm confused as to where a backup light switch would be if nss WAS also backup switch or is it likely truck was at one time manual?
Enjoying the journey but this thing is wearin me out!
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 785
From: Simi Valley, CA
No NSS if truck has a 4 M/T, backup lamp switch threads into shift tower/ 3 M/T backup lamp switch located on column, under hood...adjacent to 1st/reverse selector lever.
Backup aka reverse lights, only supposed to work when in reverse.
1978/79 F100/350, Bronco & Econoline: There are three different T/S switches:
D8TZ-13341-A .. Use with Tilt Wheel / D8TZ-13341-B .. Use with A/T without Tilt Wheel / D8TZ-13341-C .. Use with M/T without Tilt Wheel.
Does the swapped in 1978/79 steering column have a Tilt Wheel? It's operated by pressing the T/S handle forward.
Backup aka reverse lights, only supposed to work when in reverse.
1978/79 F100/350, Bronco & Econoline: There are three different T/S switches:
D8TZ-13341-A .. Use with Tilt Wheel / D8TZ-13341-B .. Use with A/T without Tilt Wheel / D8TZ-13341-C .. Use with M/T without Tilt Wheel.
Does the swapped in 1978/79 steering column have a Tilt Wheel? It's operated by pressing the T/S handle forward.
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
MikeoOoOoO,
Getting somewhat familiar with reading the techs. Found another hanging plug in engine bay that looks like a back up switch plug. Still a wild card but thinking this may be cause for fuse blowout because there is no jumper on it.
I'm confused as to where a backup light switch would be if nss WAS also backup switch or is it likely truck was at one time manual?
Enjoying the journey but this thing is wearin me out!
Getting somewhat familiar with reading the techs. Found another hanging plug in engine bay that looks like a back up switch plug. Still a wild card but thinking this may be cause for fuse blowout because there is no jumper on it.
I'm confused as to where a backup light switch would be if nss WAS also backup switch or is it likely truck was at one time manual?
Enjoying the journey but this thing is wearin me out!
If the truck was automatic, the factory installed the jumper in the picture. If it was a 3 spd. this connector was plugged into the switch and there was a dummy plug plugged into the flat connector under the dash.