What is the wire on top of my tranny?? HELP please!!

[Blk91stang]

I pulled out my old tranny to install the G-Force. On the top cover, the old one has a connector coming out of it and plugs into my factory harness. The G-Force doesn't even have a hole for the connector let alone a connector coming out of it. The only connections my new trans has is the speedometer and the plug for the backup lights. What does this extra wire coming out of my stock trans do?? Thanks

 

[GT89Mustang]

Possibly cruise control if your car has it.

 

[Mustang5L5]

Nuetral Safety Sensor.

Car will run without it.

 

[Blk91stang]

I was under the impression the neutral saftey switch was under the dash and activated by the clutch pedal being I had to adjust it because my car wouldnt start.

Doesn't cruise control branch off from the speedometer somehow?

Anyone else have any thoughts??

 

[Stang89LXCPE]

The pigtail on the top left corner of the case is a neutral switch. The one in the center of the case is for the reverse lights (two prongs). The car will run without the neutral switch hooked up.

 

[Killer50stang]

I pulled out my old tranny to install the G-Force. On the top cover, the old one has a connector coming out of it and plugs into my factory harness. The G-Force doesn't even have a hole for the connector let alone a connector coming out of it. The only connections my new trans has is the speedometer and the plug for the backup lights. What does this extra wire coming out of my stock trans do?? Thanks

Pictures?

 

[Blk91stang]

Where I circled is where the stock tranny had a threaded boss with some sensor and wires/plug hanging out which plugged into my harness. As you can see, this tranny has none of this.

Why would Ford not have a "Neutral Safety Switch" on some transmissions? Haven't noticed anything out of ordinary from it tho.

 

[Mustang5L5]

Where I circled is where the stock tranny had a threaded boss with some sensor and wires/plug hanging out which plugged into my harness. As you can see, this tranny has none of this.

Why would Ford not have a "Neutral Safety Switch" on some transmissions? Haven't noticed anything out of ordinary from it tho.

The NSS on the clutcvh pedal is the main one the car uses to prevent starting without pressing the pedal.

The NSS on the tranny is for the computer only. It senses if the tranny is in nuetral so it can begin spitting out error codes. The car will run without this sensor, but everytime you run the codes you will get "Vehicle not in nuetral, cannot run codes"

The Cruise control runs off the VSS sensor which is attached to the speedo cable. Someone told me the CC looks at the NSS on the tranny as well to sense if the trans is bumped into nuetral and kills the CC. I am unsure about this as well.

But the car will run fine without this sensor.

 

[Mustang5L5]

PS. The T-5 didn't get the NSS sensor until 1985 or so. The cover on the G-force trans is a copy of a casting of an eary t-5 cover...1983 or so.

 

[Michael Yount]

5L5 nailed it.....

 

[89MustangGX]

The NSS on the tranny is for the computer only. It senses if the tranny is in nuetral so it can begin spitting out error codes. The car will run without this sensor, but everytime you run the codes you will get "Vehicle not in nuetral, cannot run codes"

I don't know if this will affect me or not (going from an AOD to T5 -- but I have a T5 wiring harness to use if I need it), but how would you pull codes then? Just step on the clutch, or is something else needed?

 

[Michael Yount]

You can pull codes in KOEO (key on, engine off) mode; you can't pull codes in a KOER (key on, engine running) mode unless you jumper the wires on the computer (I think it's pins 46 and 30) as if it were in neutral.

 

[89MustangGX]

I don't think I've ever even tried pulling KOER codes...but good to know in case I ever do.

BTW -- my tranny has that sensor, if (or if I don't) I use the wiring harness any idea if mine would work anyway?

 

[Michael Yount]

There are also diagnostic tests you can have the computer run while the engine is running - those aren't available to you without some way of telling the ecu you're in neutral. All the pigtail/switch inside the tranny does is complete a circuit - just like the reverse lights switch. It's probably much easier to simply rig a toggle switch or even a 'spout' like connection (male/female spade connectors) down by the computer. Whenever you want to run KOER tests, just plug the connectors in or flip the toggle completing the circuit. Consult your Stang wiring diagram to see which part (wires) of the ecu harness to put the switch/connectors in.

 

[Blk91stang]

You guys rock

 

[89MustangGX]

There are also diagnostic tests you can have the computer run while the engine is running - those aren't available to you without some way of telling the ecu you're in neutral. All the pigtail/switch inside the tranny does is complete a circuit - just like the reverse lights switch. It's probably much easier to simply rig a toggle switch or even a 'spout' like connection (male/female spade connectors) down by the computer. Whenever you want to run KOER tests, just plug the connectors in or flip the toggle completing the circuit. Consult your Stang wiring diagram to see which part (wires) of the ecu harness to put the switch/connectors in.

Sounds good -- I suppose probably not worth worrying about too much unless I needed to pull those codes (and even then, it seems it might work), but I'll probably try anyway just to see.

Good info.

 

[Blk91stang]

I read that in 92' Ford did away with the neutral safety switch on top of the transmission. Also my friend with a 93' with a G-Force said he never remebered there being one on his stock one.

 

[Michael Yount]

According to Probst' book/schematics for the Ford efi, both the 88-91, as well as the 92-93 have the neutral safety switch.