Clutch switch override... Best way to go about it... - Page 3 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 11-16-2008, 06:38 PM   #41
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,326
Total Cats: 1,925
Default

Quote:
Originally Posted by Thucydides View Post
Joe, why isn't the clutch switch fried by the starter solenoid; is it a heavier load capable switch or is there something else going on?

The other thing I'm confused about is that since the switches are already wired in parallel, why doesn't the starter already engage when the transmission is in neutral?
The answer to both questions is:

Because, as I stated way back in post #10, there are two separate clutch switches. The big one at the bottom operates the interlock, and the little one up top goes to the ECU and the cruise computer.


Quote:
Also, you've "X-ed" out the starter interlock switch, which I believe is another term for the clutch switch. This switch wouldn't be removed, only supplemented by your relay circuit. Yes, no???
Again, it's only one of two switches. You can physically remove it if you wish,or you can just bypass it.


Please go back to the top and re-read this thread if you plan to keep insulting Vash in it.



edit: I still think this is silly as hell. I avoid it by not loaning my car to idiots who can't drive, and yes, this includes members of my own familily.
Joe Perez is offline   Reply With Quote
Old 11-16-2008, 07:20 PM   #42
Junior Member
 
Join Date: Jun 2008
Location: Fairfield, California
Posts: 418
Total Cats: 0
Default

Quote:
Originally Posted by Joe Perez View Post
The answer to both questions is:

Because, as I stated way back in post #10, there are two separate clutch switches. The big one at the bottom operates the interlock, and the little one up top goes to the ECU and the cruise computer.


Again, it's only one of two switches. You can physically remove it if you wish,or you can just bypass it.
Yep, it's clearer now than it was last night when I first looked at this. I didn't get that the interlock switch was not the one I'd been looking at in the wiring diagrams. Thanks; and yeah, the large bold font was a great help.


Quote:
Originally Posted by Joe Perez View Post
Please go back to the top and re-read this thread if you plan to keep insulting Vash in it.
I doubt Vash was at all insulted; if so he didn't make a fuss about it. Got your knickers in a bit of a bind, Joe?
Thucydides is offline   Reply With Quote
Old 11-16-2008, 10:45 PM   #43
Elite Member
iTrader: (15)
 
Join Date: Dec 2007
Location: San Antonio, Texas
Posts: 4,889
Total Cats: 28
Default

Joe/Thucydides I need to jack up the car soon to undercoat the backing plates for the roll bar/door bars. When I do that I'll check the open/closed mode on the neutral switch. It will probably be a few days until I get to it. I have had a couple of glasses of vino tonight, and alcohol and jack stands don't mix. Pinned under a Miata... talk about silly...

Last edited by ZX-Tex; 11-16-2008 at 10:55 PM.
ZX-Tex is offline   Reply With Quote
Old 11-17-2008, 01:00 AM   #44
Junior Member
 
Join Date: Jun 2008
Location: Fairfield, California
Posts: 418
Total Cats: 0
Default

ZX-Tex, the manual says the neutral switch is "on" when the transmission is in neutral, which is how you'd want it to function if you want to use it as a clutch switch by-pass. But it's always fun to crawl under the car to double check.

A relay and a coupe of diodes is a piece of cake. The hardest part of the job is crawling into the foot well to hook things up. You might find it easier to ignore the starter interlock switch (the red clutch switch) entirely and simply hook up the relay directly to the starter solenoid at the two "A-01" connectors, taking the signal from a wire you've run from the neutral switch. That way you can wire everything from beneath the car and from within the engine bay rather than screwing around in the footwell under the steering column. One thing you'd want to include is a fuse between the A-01 connectors, since the connection between the battery to the primary starter terminal is shown in Joe's diagram as being un-fused.

If you decide you want to wire the relay how Joe's shown it, I would only suggest taking the signal wire from the ecu side of the "clutch switch" (the green switch) because it's already wired in parallel with the neutral switch and will see the neutral switch current. But more importantly it's right next to the "starter interlock" switch; in other words, you don't even need to worry about the neutral switch, or where its wires go, at all.
Thucydides is offline   Reply With Quote
Old 11-17-2008, 01:35 AM   #45
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,326
Total Cats: 1,925
Default

Quote:
Originally Posted by Thucydides View Post
ZX-Tex, the manual says the neutral switch is "on" when the transmission is in neutral, which is how you'd want it to function if you want to use it as a clutch switch by-pass.
That's where the confusion lies. The FSM for the '99 says that pin 1V of the ECU is "On" when in neutral, however I think they are referring to that pin being a logic high, which would mean that the switch is open when in neutral:


My reasoning is as follows: The FSM also describes the clutch switch line in the same manner (again, relative to the ECU):

Then, we look at the detailed clutch switch inspection:

We know that from a mechanical standpoint, the rod on the switch is depressed when the clutch is at rest, and the rod extends when the clutch pedal is pushed in. Further, when the rod is depressed (clutch pedal not pressed) there is continuity across the switch and to ground. So when the clutch pedal is not pressed, there will be 0v on that line, and when the clutch pedal is pressed (extending the rod) the switch no longer conducts to ground, and the line will go high.

So I believe that Mazda is using the term "ON" to describe a logic high on the line in question, and not necessarily the actual state of the switch. Ergo, the upper clutch switch in the NB works backwards from that in the NA. Since the truth table also indicated "ON" (logic high) for the neutral switch when in neutral, I understand this to mean that the neutral switch is open when in neutral, and closed when in gear. This is backwards from what we need.

The overall wiring diagram seems to support this conclusion. Here are the diagrams for the NA and NB side by side:


When drawing schematic diagrams, it is the usual practice to show switches and relays in their "resting" state. The rest state for a clutch would be not depressed, and for a transmission, neutral. Note that on the NA diagram, the clutch switch is shown open and the neutral switch is shown closed. On the NB diagram, they are backwards. This would apparently confirm the reasoning that they are backwards on the NB relative to the NA.

Hence, my request for verification.


Quote:
If you decide you want to wire the relay how Joe's shown it, I would only suggest taking the signal wire from the ecu side of the "clutch switch" (the green switch) because it's already wired in parallel with the neutral switch
Again, please read fully. On the NB, the clutch and neutral switches are seperate, unlike the NA. Once we have verification of the switch modality, I'll draw a separate diagram for the NB that shows the proper use of the neutral switch line.
Joe Perez is offline   Reply With Quote
Old 11-17-2008, 01:06 PM   #46
Junior Member
 
Join Date: Jun 2008
Location: Fairfield, California
Posts: 418
Total Cats: 0
Default

Quote:
Originally Posted by Joe Perez View Post
That's where the confusion lies. The FSM for the '99 says that pin 1V of the ECU is "On" when in neutral, however I think they are referring to that pin being a logic high, which would mean that the switch is open when in neutral:


My reasoning is as follows: The FSM also describes the clutch switch line in the same manner (again, relative to the ECU):

Then, we look at the detailed clutch switch inspection:

We know that from a mechanical standpoint, the rod on the switch is depressed when the clutch is at rest, and the rod extends when the clutch pedal is pushed in. Further, when the rod is depressed (clutch pedal not pressed) there is continuity across the switch and to ground. So when the clutch pedal is not pressed, there will be 0v on that line, and when the clutch pedal is pressed (extending the rod) the switch no longer conducts to ground, and the line will go high.

So I believe that Mazda is using the term "ON" to describe a logic high on the line in question, and not necessarily the actual state of the switch. Ergo, the upper clutch switch in the NB works backwards from that in the NA. Since the truth table also indicated "ON" (logic high) for the neutral switch when in neutral, I understand this to mean that the neutral switch is open when in neutral, and closed when in gear. This is backwards from what we need.

The overall wiring diagram seems to support this conclusion. Here are the diagrams for the NA and NB side by side:


When drawing schematic diagrams, it is the usual practice to show switches and relays in their "resting" state. The rest state for a clutch would be not depressed, and for a transmission, neutral. Note that on the NA diagram, the clutch switch is shown open and the neutral switch is shown closed. On the NB diagram, they are backwards. This would apparently confirm the reasoning that they are backwards on the NB relative to the NA.

Hence, my request for verification.


Again, please read fully. On the NB, the clutch and neutral switches are seperate, unlike the NA. Once we have verification of the switch modality, I'll draw a separate diagram for the NB that shows the proper use of the neutral switch line.
This is why it's good to have folks around who understand lektricity.

Usually, I test my circuits using the smoke technique. No smoke = good; smoke = not so good.
Thucydides is offline   Reply With Quote
Old 04-13-2009, 05:18 PM   #47
Senior Member
 
Join Date: Nov 2007
Location: somewhere in NoVA
Posts: 550
Total Cats: -1
Default

Quote:
Originally Posted by Joe Perez View Post
That's where the confusion lies. The FSM for the '99 says that pin 1V of the ECU is "On" when in neutral, however I think they are referring to that pin being a logic high, which would mean that the switch is open when in neutral:


My reasoning is as follows: The FSM also describes the clutch switch line in the same manner (again, relative to the ECU):

Then, we look at the detailed clutch switch inspection:

We know that from a mechanical standpoint, the rod on the switch is depressed when the clutch is at rest, and the rod extends when the clutch pedal is pushed in. Further, when the rod is depressed (clutch pedal not pressed) there is continuity across the switch and to ground. So when the clutch pedal is not pressed, there will be 0v on that line, and when the clutch pedal is pressed (extending the rod) the switch no longer conducts to ground, and the line will go high.

So I believe that Mazda is using the term "ON" to describe a logic high on the line in question, and not necessarily the actual state of the switch. Ergo, the upper clutch switch in the NB works backwards from that in the NA. Since the truth table also indicated "ON" (logic high) for the neutral switch when in neutral, I understand this to mean that the neutral switch is open when in neutral, and closed when in gear. This is backwards from what we need.

The overall wiring diagram seems to support this conclusion. Here are the diagrams for the NA and NB side by side:


When drawing schematic diagrams, it is the usual practice to show switches and relays in their "resting" state. The rest state for a clutch would be not depressed, and for a transmission, neutral. Note that on the NA diagram, the clutch switch is shown open and the neutral switch is shown closed. On the NB diagram, they are backwards. This would apparently confirm the reasoning that they are backwards on the NB relative to the NA.

Hence, my request for verification.


Again, please read fully. On the NB, the clutch and neutral switches are seperate, unlike the NA. Once we have verification of the switch modality, I'll draw a separate diagram for the NB that shows the proper use of the neutral switch line.
So this post is old as all get out; but I am in the process of converting an auto to a manual so I had a chance to play a little.

I was trying to figure out how to best maintain OEM feel with my tranny swap and therefore was going to bypass the clutch switch and use the neutral safety switch. Well, come to find that the neutral safety switch is 50K Ohm in neutral and open in any other gear.

I still need to figure out a lot of wiring since the idle is strange and it looks like the ECU needs to know that the car is in gear somehow. My thoughts are to modify the automatic's range position switch to work in conjunction with the manual's neutral safety switch; but the question is.... how much voltage can this thing take? I need to push +12VDC through it and have it come out the other end... anyone here experiment too much with this?

Thanks all and best regards,
Prospero
Prospero is offline   Reply With Quote
Old 04-13-2009, 05:49 PM   #48
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,367
Total Cats: 1,331
Default

This is a hilariously long thread for a problem I solved with a penny and a piece of electrical tape.
Savington is offline   Reply With Quote
Old 04-16-2009, 06:27 PM   #49
Junior Member
 
kday's Avatar
 
Join Date: Aug 2008
Location: Boston
Posts: 223
Total Cats: 0
Default

"50K Ohm in neutral and open in any other gear."

That's odd. On my '90 the neutral switch is close to 0 ohms to ground when out of gear.
kday is offline   Reply With Quote
Old 09-10-2011, 08:54 PM   #50
Newb
 
Join Date: Dec 2008
Posts: 2
Total Cats: 0
Default

im gonna bump this extraordinarily long thread and give what i did.

Removed the clutch over ride box, disconnected the wiring, pulled a 15a fuse from the defroster sec. of the fuse box, twised the pegs 90degrees, inserted it into the harness connector where the original wiring plugged into. TADA!
djsqiigles is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 59 Today 09:00 PM
ACT race clutch and AASCO 7lb. aluminum flywheel graexodus Miata parts for sale/trade 5 10-26-2015 02:48 PM
3rd Time's a Charm...hopefully. zephyrusaurai Meet and Greet 2 09-28-2015 11:59 PM
Are my coils failing? viriiguy General Miata Chat 5 09-28-2015 08:39 PM


Thread Tools

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 09:33 PM.