The neutral safety switch sits on top of the tranny near the front. Has nothing to do with a clutch disengagement switch -- 2 completely different safety features. Here's an image.

https://www.google.com/search?q=t5+...om%2Fforum%2F5-0l-1979-1995-mustang%2F559346-neutral-safety-switch.html;924;702

 

Yes and No.

The switch on the transmission works in conjunction with the switch on the clutch pedal. Not the one that engages the starter as you mentioned. There is two switches on the clutch pedal. The other is wired in with the neutral switch on the transmission. So even with the trans in gear, you can have the ECM go into a neutral state by pressing the clutch down.

 

As Michael was saying, there are two switches with similar names.

The one that keeps the starter from engaging unless the clutch is pressed is under the dash attached to the clutch pedal. This one seems to be your problem.

The one on the transmission tells the ECM if it is in neutral so that it can control idle and cruise control based on being in gear or in neutral. This switch was deleted beginning in 1994.

 

Neutral safety switch?

Sooooo, is it attached at the pedal, or further up the arm?

Thank you,
Jim

JOHM 3:16

 

Jim,

Neither. It isn't connected to any part of the car chassis.

Since it tells if the transmission is in neutral or not, it is on the transmission since that is the only place a sensor could tell if the transmission is in neutral or not.

It is on the left top side of the case.

The clutch safety switch is on the side of the clutch pedal and on the opposite end of the clutch pedal shaft. If your car has cruise control, there will be two or three clutch switches. I don't remember exactly how many. One of them is for the starter interlock.

 

My 89 manual never had a neutral switch. It has a cruise disable switch, brake light switch, and clutch safety switch on the pedal assembly. The starter lockout on the clutch requires pushing the pedal very near the floor. The others just require slight movement. When I get home (I'm in Tallmadge working for a few days) I can take a picture, if there aren't some already on the net.

 

Jim - if you click on the link I provided in post #2 -- THERE IS A PICTURE that is worth, well you know.

 

Here is a picture of the switch on a pedal assembly.

This isn't exactly your setup. It appears to be on a "Classic" Mustang pedal assembly, but the switch appears to be a Fox Type switch that was adapted.

You should see something that looks pretty close to that switch under the dash attached to the clutch pedal. You may be able to adjust it...

 

Those features were bypassed on mine when the swap was done. The features became required on all US cars following the Audi unintended acceleration mishaps in the 80's. Most contemporary cars have a version of them. The ecu won't let the car start if it could unintentionally be put in motion when you turn the key to start. Most of them work the same way -- if the car's not in neutral - it won't start. On some, the clutch disengagement switch overrides the neutral safety switch - that is, if the car is in gear you can't start it UNLESS the clutch is disengaged. But on many - both functions must pass the test, that is, the car must be in neutral AND the clutch must be disengaged (press the pedal in) in order to start the car.

How is it supposed to work on the Stang liljoe?

 

One switch on the clutch interrupts the signal to the starter to keep the car from being started. Another clutch switch and the neutral switch on the transmission are used as inputs to the EEC for it to be in the correct strategy. From that standpoint, the neutral "safety" switch on the transmission has nothing to do with safety at all, since the car will start with the transmission in gear.

 

Jack nailed it perfectly Mike! And the start signal to engage the starter still travels through the transmission harness. In a manual setup, it just gets looped back around and goes to one switch on the clutch pedal and then to the starter solenoid. On an Auto trans setup, that same start circuit is routed through a neutral safety switch, and will keep the engine from starting.

Its really just a miss use of terminology. The switch on the manual trans is called a Neutral Gear Switch(NGS), while the switch on the auto trans is an actual Neutral Safety Switch(NSS). Only the latter is a safety feature.

 

Got it. But it will only start with the car in gear IF the clutch is disengaged right? If that's true (it is in all the new stuff I've owned) - then it's very much a safety feature.

 

No, if the car is in gear(manual trans), it will start as long as the clutch is down. The clutch being down is the safety feature of the system. For Auto setups, then yes, you would be correct. They won't start in gear.

Edit: I miss read your post. So yes, you are correct on all counts there. I'll leave the rest up just for reference.

 

bringing this up back from the dead...

if you get a code for a 'neutral position switch' , which switch is faulty? the clutch or trans switch?

 

code #?

 

Code 67

 

The clutch switch only cancels the code when the pedal is depressed. So typically if you get the code, it's the transmission switch or the wiring to the switch.

 

From '92 PCED...

« TA -- Neutral Drive Input»



TA1 CODE 67/522, 525 or 528 SYSTEM IDENTIFICATION


A Code 67/522, 525, or 528 resulted from the voltage being high at either:

-- Pin 10 = A/C input

-- Pin 30 = Neutral drive

while cranking the engine or during KOEO test.

Possible causes:

-- A/C circuit shorted to power

-- Clutch engage/interlock circuits open

-- Neutral drive/gear switch open

-- Damaged processor

-- Starter relay disconnected during Self-Test.

For Manual Transmissions:
3.0L SHO and 4.9L
GO to «TA7».

1.9L MA SEFI, 2.3L, 2.9L, 3.0L, 3.8L SEFI Super Charged, 4.0L and 5.0L SEFI Mass Air
GO to «TA2».

For Automatic Transmissions:
1.9L MA SEFI, 3.0L Probe
GO to «TA10».

For all other engines:
GO to «TA8».

« TA -- Neutral Drive Input»



TA8 CHECK NEUTRAL DRIVE INPUT


l Key off.

l Verify A/C is OFF, if so equipped.

l Verify transmission is in NEUTRAL or PARK.

l Disconnect processor 60 pin connector. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

l Install breakout box, leave processor connected.

l Key on, engine off.

l Measure voltage between Test Pin 30 at the breakout box and chassis ground.

l Is voltage less than 1.0 volt?

Yes
For vehicles with A/C:
GO to Pinpoint Test Step «KM40».
For all others:
REPLACE processor.

No
Go to «TA9».

« KM -- WOT A/C Cutout (WAC) A/C Demand»



KM40 CHECK A/C INPUT


Service Code 79/539 indicates that the ACC/S input to the processor was high during Self-Test.

Service Code 67 indicates that during Self-Test, voltage was high on NDS (Pin 30) or ACCS (Pin 10) circuit.

NOTE:
Before entering this test, verify A/C selector is off (and shift selector is in PARK for AXODE and E40D vehicles). If A/C was on, rerun «Quick Test». If code 67 or 79/539 is present, continue with this test.

l Disconnect processor 60 pin connector. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

l Install breakout box, leave processor disconnected.

l Key on, engine off.

l Measure voltage between Test Pin 10 at the breakout box and chassis ground.

l Is voltage greater than 1.0 volt?

Yes
SERVICE short to power in A/C circuit. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test».

No
For trucks with two digit codes and E40D transmission:
GO to «KM41».
For all others:
REPLACE processor. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test».

« TA -- Neutral Drive Input»



TA9 CHECK NEUTRAL DRIVE SWITCH


l Key off.

l Breakout box installed, processor disconnected.

l Locate the Neutral Drive Switch.

l Disconnect vehicle harness from the Neutral Drive Switch and measure resistance across the switch.

l Is resistance less than 5.0 ohms?

Yes
SERVICE open in vehicle harness Neutral Drive circuit. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test».

No
REPLACE Neutral Drive Switch. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test».

 

Just curious if I don't have a trans in the car will the starter turn over? I'm trying to get my motor to fire up before I buy a transmission.

 

trans has NO affect on start circuit

its the wiring