Neutral Safety Switch Wiring

[BridgeStreetBlues]

I have a TF999 and an aftermarket shifter that has it's own neutral safety switch with 2 wires connected. The reverse lights are wired to a toggle switch and it has two wires. What I want to do is put the stock plug back on. If I have the correct plug, it only has 3 wires. Is this correct and
how do I wire the stock plug if I have 4 wires?


View attachment 9744

 

[bondo258]

Make sure your reverse lights aren't on a relay. previous owners who add switches, may have added relays. And cut wires.

The connector from the main engine bay harness, to the tranny extension is behind the large cowl fresh air tube. Make sure it is intact/plugged in.

(I think it was a four wire plug, and the orange was for Transfer Case switch.)

Anyhow.

The Three pin round plug.

Red should be hot w/ignition on.

White w/ trace is backup lamps, Just like in rear.

Black is ground to solenoid.

It connects to the starter solenoid bottom post. I have a standard tranny solenoid, without post, because sometimes you need to get the motor running after a stall-Quickly.

The switch grounds out through the body of the tranny switch, to provide a ground for the solenoid. Without a ground, the solenoid doesn't work.

You can wire a secondary switch for backup lamps, anywhere on the White w/trace wire. I have mine done up this way. I'd use a relay, and separate fuse doing it his way, though.

Also Your shifter linkage may be shot. My brand new switch wouldn't work even remotely correct until I rebuilt my shifter linkage. The linkage supports the shift arm, which must have no wobble in it's travel.

Any lateral movement = little / no contact with switch.

Mine was a Real PITA to rebuild, Yours is probably more accessible. Kits are available, but the parts need some tweaking to work.

I needed two kits to finish one complete assembly.

I run a Column shift on mine, though. and 727 tranny has same shift arm as 999.

 

[BridgeStreetBlues]

Thanks for the reply. There are a few things I can tell you. The set up I have does work, I just really wanted to eliminate the reverse light toggle. They keep breaking and if I ever use it, I forget to turn it off. It also has no relay wired in just a toggle.
The plug wires are different colors than you mentioned. They are 1) black, 1)purple and black, and 1)brown with yellow. I would be happy to just hook up the reverse lights to it....

 

[bondo258]

Purple/black to backup lights. Check.

brown/yellow to starter solenoid. Check.

White/tan ignition hot ( + ). Um. The Black? is it in the center? or on a side?

Check for voltage at the plug with ignition switch "on" to be sure.

The first and last should complete the backup circuit. The middle should complete the starter solenoid grounding circuit.

Since the harness fits the switch both ways.

 

[BridgeStreetBlues]

The black is on one side the black and purple is on the other and the tan/yellow is in middle. I still don't know what to do with the other wire on the safety switch on the shifter. The harness is probable a "painless" and my body is Glass if that makes a difference/grounding..I have a Lokar floor shifter with a neutral safety switch that works and it has two wires to it. I also have a toggle switch with two wires that work the reverse lights. So I want to go back to the stock plug that goes to the neutral safety switch in the tranny and eliminate the toggle and the other safety. If the two wires from the reverse lights toggle go to the outside two wires on the stock plug, where do the two wires from the neutral safety switch on the shifter go, if there is only one wire left coming out from the stock plug?
..or just do the reverse lights only to the plug and call it a day?

 

[bondo258]

I'd do the reverse and call it a day. You can work on it later.

Starting an engine "in gear", on an automatic really doesn't cause much wear and tear, as far as I know.

The only risk is bumping the ignition switch while driving/engine running in park. Bad news for starter and flexplate/ring gear.

It is more a safety feature, much like in newer vehicles you need to put your foot on the brake, to shift out of park.

In a standard vehicle with a starter interlock, (clutch or brake depressed to start) I believe it's an excellent feature.

Off-road stuff sometimes requires a fast restart "in gear". You lose power brakes/steering if the engine stalls. Sliding backwards down hill because you lost traction when you stalled isn't the best time to shift into "park".

To answer your question a 'glass body shouldn't effect the ground from the Transmission . Its bolted to the engine. Your engine is grounded. How well? good enough for your ignition system to work. If the switch is bad, or the shift arm is sloppy, all bets are off. Replaced mine a few months ago. it was 16 dollars.

If your tranny was replaced at any point you may have got a tranny harness from a model besides CJ.

All the three prong NSS are alike. Which ever terminal grounds out in park/neutral only is for starter solenoid. (if the switch is OK)

The other two are reverse lights. Either terminal should work for your Rev. connection or power. It's an insulated switch. They can be wired either/or, and function safely.

 

[BridgeStreetBlues]

OK I think I get how the shifter safety switch is wired after looking again and tracing the wires. I could eliminate it if I wanted but I will probably just eliminate the reverse light toggle and wire it to the tranny plug. My rig is far from stock. It has been changed many times over before and since I have had it. It also has MSD ignition and no bottom post on the solenoid, so I don't know if I'll ever figure out the wiring from the tranny to the solenoid for the stock set up to work. I'll leave well enough alone on that, especially since the shifter safety switch works anyway. The reverse light toggle is what I really wanted to eliminate. Thanks for all the help.

 

[PetesPonies]

Only three wires are needed. The neutral safety switch is a pass through ( series ) switch. Power from the ignition switch is run through the NSS and on to the solenoid. Power for the reverse lights need only one wire. Once this wire is connected in the circuit, grounds are at the lamps themselves or in the harness as needed. Your power into the NSS will energize both the solenoid and the reverse lights. Simply, 1 in, 2 out.

 

[bondo258]

Power from the ignition switch is run through the NSS and on to the solenoid.

NO. The Starter solenoid low side receives GROUND (-) from the NSS.

The ignition circuit provides the HOT (+)

Maybe it's different on older Jeeps, or column/floor mount NSS - Automatics.

 

[BridgeStreetBlues]

Power for the reverse lights need only one wire. QUOTE]


Mine are somehow wired with two to a toggle switch....I tried to trace them but get lost behind dash...


I'm trying to go from this type of switch on the floor mount shifter to the plug for the 3 prong switch on the tranny in these pics, my reverse lights are wired with two wires and a toggle giving me 4 wires going to 3 on the plug

View attachment 9806 shifter NSS

View attachment 9809 tranny NSS

View attachment 9807 tranny NSS plug

 

[PetesPonies]

NO. The Starter solenoid low side receives GROUND (-) from the NSS.

Wow. Not sure where you read info like this, but you don't understand how the circuit works. Let's start here.

First a "Ford" style solenoid needs power given to the control side of the relay to energize the electromagnet. That comes from the ignition switch, with the NSS standing in it's way. There is no power to this control circuit other than the ignition switch. Once the electromagnet is energized the contact is pulled down, the controlled circuit is completed allowing continuity from the battery terminal to the starter terminal. The engine spins.

Here is a diagram I found quickly. All you have to do is trace the wires. This is the way a typical starting system works. I have worked on so many over many different brands, they all work the same way.

http://www.jeepz.com/forum/attachme...cj5-wiring-diagram-cj-wiring-diagram-1979.jpg

 

[bondo258]

Didn't "read" it anywhere. A ford-style remote mount starter solenoid for AT needs the safety lug grounded to function.

Like I said, other configurations may work differently, but the three-pin Auto tranny mount NSS gives ground to the solenoid.

The schematic you posted does not have the three pin switch used in automatics, which is what the poster was asking about, and you pontificated about.

you don't understand how the circuit works

I understand you need to refer to the proper schematic for the proper information. Well that, and listening to the question being asked.

 

[PetesPonies]

Hmm, my credentials?? I taught auto in the school system for 30 years, retired now. I own an automobile restoration business, been doing this for over 20 years now. I think I understand how the circuits work. What you are saying is totally wrong. I showed the schematic so you or others can see the circuit, follow the wires yourself. This circuit in the diagram shows both automatic and manual. There is no switch for a manual, just a jumper which is in the circuit. Sorry Bondo, what you are saying just isn't right.

 

[BridgeStreetBlues]

 

[bondo258]

Your diagram doesn't show a three- pin tranny switch.

Where you work or used to work doesn't effect that.

Even if it did, it wouldn't show you the internal FUNCTION of the switch or the solenoid, just pin-outs.

In an Automatic Starter Solenoid, the trigger circuit is isolated and only receives ground through the NSS lug on the bottom.

It is not like the one used in standards, where the Bracket serves as ground.

Sounds like the OP has a Standard tranny wired jeep, with an Automatic installed.

Pete. Chill dude. Jeeps are supposed to be fun.

 

[BridgeStreetBlues]

You may be right about it having been a wired for a stick. That seems to make sense. I did trace the wires from the NSS on the shifter, and they were spliced in just after the ignition switch by the PO. I could not trace the reverse light wires all the way.
I think I'm going to leave it alone for now. Plenty of other work to do this weekend. Rebuilt tranny is already in, re-sealed Transfer Case going back in Saturday, re-connect exhaust, install crossmember, and wait for my new rear driveshaft. I'll figure this plug out later...

 

[PetesPonies]

Where I work . . means nothing. What I do and have done means lots. I know how these circuit operate. Point being, I taught these circuits. This IS fun, I just don't allow misinformed information to run rapid on the net when I can help it. We all want accurate information to draw from.

 

[bondo258]

Here's a little blurb from a guy named John Strenk, a well-known Jeep expert:

Like one of these:

http://www.moparts.com/Tech/Archive/auto/5.html

Looks like the center terminal is used as the Safety switch. and the outer 2 for the backup lights. Prevent hooking it up backwards. Your always in the right configuration.

The Neutral Safety Switch (NSS) on an 76 -77 CJ7 (CJ5 's never had an automatic) realy was on the colume. Standard GM Issue. Even have the jumper in my harness. In 84 on they did have them in the tranny. What a DJ had I don't know.

Here is a 76 harness:

It's the center plug with the jumper and two blue wires. In a CJ7 with QuadraTrac tranny this was plugged into the switch on the colume


When a NSS is on the tranny you need a special Starter solenoid. THese have 3 little post on them. 1 post is marked "I" and goes to the ignition (+) coil. THe Second one is marked "S" and goes to the Start on the ignition switch. THis is common on both types of starter solenoid. The 3rd post,on the backside or bottom, goes to the tranny NSS.

Automatic Starter Solenoid


On a solenoid for a manual tranny the coil is grounded on one side to the mounting studs. One for a later model CJ with an automatic the coil is isolated and the wire that usually runs to the mounting tabs now runs to the 3rd post.

It is a common mistake to put in a solenoid without the 3rd post. You probably won't notice a difference until you suddenly notice you can start it in gear. My 84 wiring harness has the NSS in place but not used. Anyway my quess is you don't have the third terminal on your solenoid.

It's part a larger discussion found here: Nuetral Safety Switch & Backup Light - JeepForum.com

I would have linked to a clearer explanation, with diagrams and such, but the links are dead. Seeing as Mr. Strenk is an EXPERT and has done numerous write-ups regarding Jeep wiring peculiarities and troubleshooting procedures, I'll take his word. Don't take my word, google John Strenk Jeep

Also I had to wire up my 85 for an AT, 3-pin switch. I keep my safety lug grounded when wheeling, in case I need to start "in gear". Guess what? The circuit works exactly like both I and the man quoted above says it does.

I just don't allow misinformed information to run rapid on the net when I can help it

Same here, bub.

Comment on systems you've actually worked on, in the vehicles being discussed, and mis-understandings like this won't happen again.

 

[clipselpz2]

So did anyone ever figure out how the wiring goes or have a diagram?