Electrical Need help with cruise control and NSS.

brent89GT · Jul 13, 2023

I purchased an 89 GT. Was and AOD car and was swapped to a T5. My question is. The NSS wasn't hooked up. There seems to be 2 plugs on the sensor attached to clutch pedal. What 2 wires plug in to that. I think one goes to Trans mission harness not sure the other. Next question is on cruise control. It's not working. Does anyone have diagrams concerning either if theses 2 issues. The guy that built car told me everything is there for cruise control but needs the harness. I'm picking car up today so haven't looked that over but was trying to get a Jumpstart on parts. I was able to talk to guy that built the car and he was telling me these 2 issues. I posted a pic of speed control amplifier. Where do the 2 plugs come from in pic?
Thanks for any help.

Mustang5L5 · Jul 13, 2023

There are two plugs that connect to the clutch switch.

The brown plug is the clutch safety/starter interrupter circuit. Red wire with blue stripe. This is for the starter circuit and the car will not start unless this circuit is closed. On the AOD cars there is a jumper (pictured above) and on the 5-spd cars it plugs into the clutch switch and closes with the clutch pressed in. THERE IS NO NUETRAL SAFETY ON 5-SPD CARS. The NSS is on the AOD only, and gets jumped out on the 5-spds in the Reverse harness under the car.

The clear plug is the NGS or Nuetral Gear Switch. It's only purpose is to inform the ECU if the trans is in gear for the purpose of code dumping and it may affect idle strategy a bit (i haven't confirmed this in the ECU code yet). It's wired in parallel with the plug on the top of the T5 that most people incorrectly think is the NSS. They work together to tell the ECU when the car is in neutral by way of clutch in, or T5 in N, for the sole purpose of code reading/idle and does nothing with the starter circuit.

AOD cars do not have the correct plug in the trans harness for the NGS that plugs in to the top of the T5. What sometimes happens is that the car will have a hanging idle when sitting at stop light with clutch out, and trans in neutral. Pressing the clutch in sometimes gets the idle to drop. I've recommended folks just unplug the NGS plug from the clutch pedal and stick a 5A blade fuse in to see if that solves the hanging idle issue.

As for cruise control. See this thread and see if it answers any questions you have or respond in there if you have additional questions. C220 on your diagram comes from the cruise control servo in the fender. It pokes through a grommet in the far left corner of the dash where the outer fender is. C221 is in the vehicle harness somewhere. All fox models will have C221 existing

Foxbody Mustang Cruise Control information, location, wiring diagrams

Done a little research into this and figured what I learned should be put into a thread and added to the tech sticky. As you can imagine, nobody really gives much thought to cruise control on these cars, so many searched threads had dead ends. So many this will help someone out down the road...

stangnet.com

Heres the cruise servo. The plug to the right would be C220. You can see the grommet that would poke through the firewall middle of that wiring harness.

AeroCoupe · Jul 13, 2023

This does not apply to your car as it is for the 91-93 4 cylinder cars that are swapped to a V8 and T5 but it does address the harness that is needed for the NGS on the top of the T5 to provide a closed or open circuit to the EEC.

Drivetrain - 91-93 Four Cylinder Five Speed Cars - No Neutral Gear Switch (NGS) Wiring

Went through the T5 and have it back in the car and I decided to finally look into why the NGS has no place to plug in on the car. After some digging around what I am understanding is the four cylinder T5 cars starting in 91 no longer have the NGS. My car was originally a four cylinder that I...

stangnet.com

brent89GT · Jul 13, 2023

Mustang5L5 said:
There are two plugs that connect to the clutch switch.

The brown plug is the clutch safety/starter interrupter circuit. Red wire with blue stripe. This is for the starter circuit and the car will not start unless this circuit is closed. On the AOD cars there is a jumper (pictured above) and on the 5-spd cars it plugs into the clutch switch and closes with the clutch pressed in. THERE IS NO NUETRAL SAFETY ON 5-SPD CARS. The NSS is on the AOD only, and gets jumped out on the 5-spds in the Reverse harness under the car.

The clear plug is the NGS or Nuetral Gear Switch. It's only purpose is to inform the ECU if the trans is in gear for the purpose of code dumping and it may affect idle strategy a bit (i haven't confirmed this in the ECU code yet). It's wired in parallel with the plug on the top of the T5 that most people incorrectly think is the NSS. They work together to tell the ECU when the car is in neutral by way of clutch in, or T5 in N, for the sole purpose of code reading/idle and does nothing with the starter circuit.

AOD cars do not have the correct plug in the trans harness for the NGS that plugs in to the top of the T5. What sometimes happens is that the car will have a hanging idle when sitting at stop light with clutch out, and trans in neutral. Pressing the clutch in sometimes gets the idle to drop. I've recommended folks just unplug the NGS plug from the clutch pedal and stick a 5A blade fuse in to see if that solves the hanging idle issue.

As for cruise control. See this thread and see if it answers any questions you have or respond in there if you have additional questions. C220 on your diagram comes from the cruise control servo in the fender. It pokes through a grommet in the far left corner of the dash where the outer fender is. C221 is in the vehicle harness somewhere. All fox models will have C221 existing

Foxbody Mustang Cruise Control information, location, wiring diagrams

Done a little research into this and figured what I learned should be put into a thread and added to the tech sticky. As you can imagine, nobody really gives much thought to cruise control on these cars, so many searched threads had dead ends. So many this will help someone out down the road...

stangnet.com

Heres the cruise servo. The plug to the right would be C220. You can see the grommet that would poke through the firewall middle of that wiring harness.

Thank you. I actually found your post concerning this after I posted. So let me ask this. What keeps the car from being able to be cranked up in gear without the clutch being pressed in. That's what I'm wanting to fix? Is this the ngs that you speak of and I was calling it the nss? The ngs is the switch connected to clutch pedal.

AeroCoupe · Jul 13, 2023

NGS is the neutral gear switch on top of the T5. NSS is the neutral safety switch on the clutch pedal assembly. The NSS is what you want to hook up so that the car will not start without the clutch depressed. Be warned that the NSS may or may not work. Very easy to remove and easy to test.

LMR video on how to remove and install:

Another video that shows the actual wiring:

I believe the gray plug is the starter interrupt circuit and the black plug goes back to the ECU. You can take a DVM and probe the two wires associated with each plug and see if the switch is functioning properly.

Mustang5L5 · Jul 13, 2023

brent89GT said:
Thank you. I actually found your post concerning this after I posted. So let me ask this. What keeps the car from being able to be cranked up in gear without the clutch being pressed in. That's what I'm wanting to fix? Is this the ngs that you speak of and I was calling it the nss? The ngs is the switch connected to clutch pedal.

The starter interrupter circuit is what keeps the car from starting without the clutch being pressed in. Brown plug. Red/blue stripe wire. This is essentially the nuetral safety but it’s not called that.

There is NO nuetral safety on the 5-spd cars. It’s clutch safety only. The AOD cars use it but it’s jumped on the 5-spd cars

Here is where it is jumped. Reverse harness on the t5. The red/blue stripe wire loops here and is in series with the clutch interrupt circuit. Same color wires as on the clutch switch. Normally on the AOd those two wires would plug into the neutral sensor on the aod and it’s jumped out on the 5-spd cars. One circuit doing esssentially two different things. For 5-spd cars it’s just jumped out and the clutch is your safety.

brent89GT · Jul 15, 2023

AeroCoupe said:
NGS is the neutral gear switch on top of the T5. NSS is the neutral safety switch on the clutch pedal assembly. The NSS is what you want to hook up so that the car will not start without the clutch depressed. Be warned that the NSS may or may not work. Very easy to remove and easy to test.

LMR video on how to remove and install:

Another video that shows the actual wiring:

I believe the gray plug is the starter interrupt circuit and the black plug goes back to the ECU. You can take a DVM and probe the two wires associated with each plug and see if the switch is functioning properly.

Thank you for the info. Picked car up last night so haven't had a chance to go over things yet. Thank you for the info!!!

brent89GT · Jul 22, 2023

brent89GT said:
Thank you for the info. Picked car up last night so haven't had a chance to go over things yet. Thank you for the info!!!

Mustang5L5 said:
There are two plugs that connect to the clutch switch.

The brown plug is the clutch safety/starter interrupter circuit. Red wire with blue stripe. This is for the starter circuit and the car will not start unless this circuit is closed. On the AOD cars there is a jumper (pictured above) and on the 5-spd cars it plugs into the clutch switch and closes with the clutch pressed in. THERE IS NO NUETRAL SAFETY ON 5-SPD CARS. The NSS is on the AOD only, and gets jumped out on the 5-spds in the Reverse harness under the car.

The clear plug is the NGS or Nuetral Gear Switch. It's only purpose is to inform the ECU if the trans is in gear for the purpose of code dumping and it may affect idle strategy a bit (i haven't confirmed this in the ECU code yet). It's wired in parallel with the plug on the top of the T5 that most people incorrectly think is the NSS. They work together to tell the ECU when the car is in neutral by way of clutch in, or T5 in N, for the sole purpose of code reading/idle and does nothing with the starter circuit.

AOD cars do not have the correct plug in the trans harness for the NGS that plugs in to the top of the T5. What sometimes happens is that the car will have a hanging idle when sitting at stop light with clutch out, and trans in neutral. Pressing the clutch in sometimes gets the idle to drop. I've recommended folks just unplug the NGS plug from the clutch pedal and stick a 5A blade fuse in to see if that solves the hanging idle issue.

As for cruise control. See this thread and see if it answers any questions you have or respond in there if you have additional questions. C220 on your diagram comes from the cruise control servo in the fender. It pokes through a grommet in the far left corner of the dash where the outer fender is. C221 is in the vehicle harness somewhere. All fox models will have C221 existing

Foxbody Mustang Cruise Control information, location, wiring diagrams

Done a little research into this and figured what I learned should be put into a thread and added to the tech sticky. As you can imagine, nobody really gives much thought to cruise control on these cars, so many searched threads had dead ends. So many this will help someone out down the road...

stangnet.com

Heres the cruise servo. The plug to the right would be C220. You can see the grommet that would poke through the firewall middle of that wiring harness.

Ok...so I was just under the dash. Found the black plug with a fuse stuck in it. If I plug this back into the clutch switch is this gonna keep car from starting without clutch push in? Also if I remove the lower dash panel under steering wheel is this gonna give me a better view of the wiring at the pedals? Again, thank you.

nickyb · Jul 22, 2023

If there is a fuse in it that usually means the switch is bad and they bypassed it with the fuse.
my fat a ss needs the driver seat removed to get under the dash easier.

brent89GT · Jul 22, 2023

nickyb said:
If there is a fuse in it that usually means the switch is bad and they bypassed it with the fuse.
my fat a ss needs the driver seat removed to get under the dash easier.

Same here on the fat ass part. It'll come out when I get to fixing something under there...lol

General karthief · Jul 22, 2023

I'm a slender guy (I also like long walks on the beach but that's a different thread) and I pull the seat if I gotta do anything extensive under there.

limp · Jul 22, 2023

General karthief said:
I'm a slender guy (I also like long walks on the beach but that's a different thread) and I pull the seat if I gotta do anything extensive under there.

My Mom always called me " husky " and I take the seat out too... Its the ONLY way to work under the dash...

Electrical Need help with cruise control and NSS.

brent89GT

New Member

Attachments

Mustang5L5

That is…until I whipped out my Bissell

Foxbody Mustang Cruise Control information, location, wiring diagrams

AeroCoupe

lube between the nut and the face. I know my lubes

Drivetrain - 91-93 Four Cylinder Five Speed Cars - No Neutral Gear Switch (NGS) Wiring

brent89GT

New Member

Foxbody Mustang Cruise Control information, location, wiring diagrams

AeroCoupe

lube between the nut and the face. I know my lubes

Mustang5L5

That is…until I whipped out my Bissell

brent89GT

New Member

brent89GT

New Member

Foxbody Mustang Cruise Control information, location, wiring diagrams

nickyb

I gotta say i never painted my nuts, Never Ever

brent89GT

New Member

General karthief

wonder how much it would cost to ship you a pair

limp

wrap a little cheese around it and its a done

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Electrical Need help with cruise control and NSS.

New Member

Attachments

That is…until I whipped out my Bissell

lube between the nut and the face. I know my lubes

New Member

lube between the nut and the face. I know my lubes

That is…until I whipped out my Bissell

New Member

New Member

I gotta say i never painted my nuts, Never Ever

New Member

wonder how much it would cost to ship you a pair

wrap a little cheese around it and its a done

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