Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Go Back   Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum > General > Tech Talk > S Chassis

S Chassis Technical discussion related to the S Chassis such as the S12, S13, S14, and S15.


Reply
 
Thread Tools Display Modes
Old 07-16-2018, 06:09 AM   #1
KoukiMonsta
Nissanaholic!
 
KoukiMonsta's Avatar
 
Join Date: Mar 2009
Location: NC
Posts: 1,969
Trader Rating: (23)
KoukiMonsta is a well-known jackass
Feedback Score: 23 reviews
SR/KA Neutral switch - normally open?

Talkin' Sr or KA manual trans.

Is the neutral switch the same as the reverse/5th gear switch?

I was under the assumption the neutral switch went to ground when in neutral, so ECU would see ground at that terminal when in neutral. I just assumed this for whatever reason.

But my trusty multimeter tells me that ain't true. The switch is normally open, meaning open in neutral and closed in gear.

I can't trust that the switch I have in that spot is correct, it 'could' be a reverse switch for all I know...unless they are all the same?
__________________
@UpshiftEngineering
KoukiMonsta is offline   Reply With Quote
Sponsored Links
Old 07-16-2018, 07:46 AM   #2
onehundredoctane
Post Whore!
 
onehundredoctane's Avatar
 
Join Date: Oct 2006
Location: Greensborough, NC
Posts: 2,783
Trader Rating: (3)
onehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfection
Feedback Score: 3 reviews
That's backwards. . . the only way that it could work is if the neutral safety switch was closed when in neutral, to complete that circuit and allow 12v to go to the starter.
onehundredoctane is offline   Reply With Quote
Old 07-16-2018, 08:06 AM   #3
LoSt180
Zilvia FREAK!
 
LoSt180's Avatar
 
Join Date: May 2013
Location: MD
Posts: 1,049
Trader Rating: (18)
LoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond repute
Feedback Score: 18 reviews
The neutral switch has nothing to do with the starter interlock. That comes from a switch on the clutch pedal, or park/neutral sensor in an auto trans.

Last edited by LoSt180; 07-18-2018 at 06:04 AM..
LoSt180 is offline   Reply With Quote
Old 07-16-2018, 10:04 AM   #4
KoukiMonsta
Nissanaholic!
 
KoukiMonsta's Avatar
 
Join Date: Mar 2009
Location: NC
Posts: 1,969
Trader Rating: (23)
KoukiMonsta is a well-known jackass
Feedback Score: 23 reviews
I am NOT describing the switch on the clutch pedal.

It COULD work either way, it depends how the ECU functions - which is the whole point of my question. I do not know how it functions.
__________________
@UpshiftEngineering
KoukiMonsta is offline   Reply With Quote
Old 07-16-2018, 11:56 AM   #5
LoSt180
Zilvia FREAK!
 
LoSt180's Avatar
 
Join Date: May 2013
Location: MD
Posts: 1,049
Trader Rating: (18)
LoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond reputeLoSt180 has a reputation beyond repute
Feedback Score: 18 reviews
The ECM detects the park/neutral position when continuity with ground exists.

When the gear position is in neutral, the PNP switch is "ON".

In electrical terms, the switch "closes" the circuit when in neutral, and "opens" the circuit in any other position.

Here's the circuit diagram for the neutral position switch. Drawing is the same for all S-chassis manuals I have on hand.



The KA 5th position and reverse switches function the same way.
LoSt180 is offline   Reply With Quote
Old 07-16-2018, 02:06 PM   #6
KoukiMonsta
Nissanaholic!
 
KoukiMonsta's Avatar
 
Join Date: Mar 2009
Location: NC
Posts: 1,969
Trader Rating: (23)
KoukiMonsta is a well-known jackass
Feedback Score: 23 reviews
Quote:
Originally Posted by LoSt180 View Post
The ECM detects the park/neutral position when continuity with ground exists.

In electrical terms, the switch "closes" the circuit when in neutral, and "opens" the circuit in any other position.
The thing is, using a multimeter and probing the leads, this is not true.

In neutral I have zero, open, continuity. In gear I have continuity.

I think I am going to remove the switch, PITA to get to tho..and confirm my sanity as to whether is is NO or NC.

It's bee a long time since I had a tranny open, but I am not visioning how this would work - unless the switch is normally closed. I don't see any way the switch could be depressed in any shifter position other than neutral.
__________________
@UpshiftEngineering
KoukiMonsta is offline   Reply With Quote
Old 07-17-2018, 07:42 AM   #7
onehundredoctane
Post Whore!
 
onehundredoctane's Avatar
 
Join Date: Oct 2006
Location: Greensborough, NC
Posts: 2,783
Trader Rating: (3)
onehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfectiononehundredoctane is close to perfection
Feedback Score: 3 reviews
I know it's not "advised". . . but you can bypass it so the car will start regardless.

Several cars I've owned were this way since they were originally autos.
onehundredoctane is offline   Reply With Quote
Old 07-18-2018, 05:33 AM   #8
KoukiMonsta
Nissanaholic!
 
KoukiMonsta's Avatar
 
Join Date: Mar 2009
Location: NC
Posts: 1,969
Trader Rating: (23)
KoukiMonsta is a well-known jackass
Feedback Score: 23 reviews
Quote:
Originally Posted by onehundredoctane View Post
I know it's not "advised". . . but you can bypass it so the car will start regardless.

Several cars I've owned were this way since they were originally autos.
this switch, located on the rear end of the transmission, has nothing at all to do with that.

This is strictly input the the ECU.

I am wiring the car from scratch, and it sure as shit doesn't have the clutch interlock switch.
__________________
@UpshiftEngineering
KoukiMonsta is offline   Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 02:30 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
vB.Sponsors
Copyright ? 1998 - 2022, Zilvia.net