Clutch switch bypass switch

[Ryan]

Clutch switch bypass switch


I want to put a switch into the dashboard of my 94 GS in the place of the 93 style hazard switch blank, that allows the passenger to press and hold the button while starting the car using the key, so that they don’t have to press the clutch pedal.

Okay, first of all, I’d like to say I’m pondering this for a few reasons:
- Its reallycold here, and its nice if the passenger can start the car.
- I park the car so that the passenger side is closest to the house
- I hate half-sitting in the car and getting my snowey shoes in the car more than I have to
- I like to think I have a lot of spare time

Here’s the basics of the plan:
-The switch itself will be like the ‘cruise off’ switch in that it will spring back to a position. You must press and hold the switch in order to start the car, similar to the clutch.
-The clutch switch will still operate normally
-I would like to work in the neutral switch, so that there is no chance of starting the car in gear by using this switch
-I am thinking that I will primarily put this switch in parallel with the clutch switch. In one side of the wire to the new switch, I would like to put in the interrupter component, relying on the neutral switch.

Research Blah Blah

NEUTRAL SWITCH:

-According to this physical diagram the switch is on the top of the transmission (mostly new to V6’s, excuse my need to include new knowledge) http://www.mx-3.com/manuals/showimg.php ... J2-016.gif" onclick="window.open(this.href);return false;

-After much scrounging, I found the MTX neutral switch in section F2, of all places, not the transmission section: http://www.mx-3.com/manuals/showimg.php ... F2-158.gif" onclick="window.open(this.href);return false;

-Also in the wiring diagrams: http://www.mx-3.com/manuals/showimg.php ... /Z-042.gif" onclick="window.open(this.href);return false;

Input - from ECM (BR/Y)
Output – GND (B)
Neutral - closed circuit
Gear - open circuit

So I may use this switch to power a relay (trigger) in order to fire the relay, close the clutch switch bypass switch, unless there is an easier way.


CLUTCH SWITCH:

The clutch switch is B/R and B/L where BR is on the starter side, and B/L is ‘after’ the switch, before the ignition switch. Circuit closed when clutch depressed, and open when not depressed.


Problems I forsee:
-The relay firing every time I change gears. (gear - neutral - gear)
-Messing with the neutral switch circuit by adding the relay trigger circuit in parallel, or series... messes with it.
- Is the input voltage from the ECM to the neutral switch enough to operate the relay trigger?

What else can I use aside from a relay? I'm not extremely apt with this kind of thing... how can I use a signal as a switch to open or close another circuit? I thought relays were only for a signal operating a higher power circuit...


Feedback welcome

Ryan

[Mooneggs]

I am actually very interested in this since I currently have to depress the neutral safety switch by hand to start my car (which involves reaching my hand up under my clutch pedal every time I start my car )

[PoisonDrop]

That's easy. Just wire a relay to bypass the clutch switch, like you said, and use the neutral switch for the relay power. I'm pretty sure that's the easiest way. Even if it gets power every time you shift, it won't really matter unless you press the button while shifting and turning the key. But who would do that?

You really just need to figure out if the wire from the neutral switch to the ECM is power or ground. Either way, the relay doesn't take that much power to operate, so you should be fine to tap into that wire.

[PoisonDrop]

Taking another look at your post, it looks like it should be ground, since there's no power provided to the switch. You should test it anyway, though.

If it is in fact ground, you are definitely good to go. Just give the relay constant power and hook it up like you said.

[2fazed]

I put a push button start on my GS. Don't have to push the clutch in at all. I attached my button to the left side of my drivers seat. All I did was disconnect the adapter on the clutch switch under the dash, on top of the clutch pedal. Spliced the two wires, and ran it to my seat. That's it, done in 10 minutes.

[Ryan]

Okay, I'm maybe a bit confused concerning the operation of relays...

are they not:

The trigger circuit is the coil of wire that, when charged, magnetically moves the shuttle and closes the power circuit? if the trigger circuit loses power, the shuttle is moved back.

So, am I correct in using the neutral switch as the trigger, and the clutch as the power?

Even if it gets power every time you shift, it won't really matter unless you press the button while shifting and turning the key. But who would do that?

I wasn't concerned about that, I was concerned about the relay ticking 500 times a day. I hope the relay is quiet, then.

You really just need to figure out if the wire from the neutral switch to the ECM is power or ground. Either way, the relay doesn't take that much power to operate, so you should be fine to tap into that wire.

The one wire is power from the ECM, and the other wire goes to ground. Check out the diagram: http://www.mx-3.com/manuals/showimg.php ... /Z-042.gif" onclick="window.open(this.href);return false;

I think I'll tap into it in series. Yes, because parallel doesn't make sense.

Bah, I keep looking at the diagram and getting confused. apparently the clutch switch and the netural switch work from the same source. Its possible for them both to be 'closed' at once, for parallel resistance. The input to the switches is from the same pin. I'm curious if its simply 12v. I need to draw it.


Note: the neutral switch kills cruise. Thats the function. (because you can pull a car out of gear without touching the clutch or brake)

[Inodoro Pereyra]

Ryan: you don't need a relay at all. The clutch switch does not handle high current.
Just wire your switch in parallel with the clutch switch, and you're done.

[Ryan]

but I WANT the neutral switch involved.

[PoisonDrop]

Ryan: you don't need a relay at all. The clutch switch does not handle high current.
Just wire your switch in parallel with the clutch switch, and you're done.

Yes, as long as your switch is high current as well. But then you lost the ability to hook into the neutral switch.

The trigger circuit is the coil of wire that, when charged, magnetically moves the shuttle and closes the power circuit? if the trigger circuit loses power, the shuttle is moved back.

That is true.

So, am I correct in using the neutral switch as the trigger, and the clutch as the power?

Sort of. You need to use BOTH the neutral switch AND a button as the trigger. That way the button won't operate unless the neutral switch is active.

I was concerned about the relay ticking 500 times a day. I hope the relay is quiet, then.

If you hook it up this way, the relay won't be ticking unless you're pressing the button.

The one wire is power from the ECM, and the other wire goes to ground.

Sort of. The wire that goes to the ECM gets grounded when the neutral switch is active. That's the wire you want to tap in to.

Bah, I keep looking at the diagram and getting confused. apparently the clutch switch and the netural switch work from the same source. Its possible for them both to be 'closed' at once, for parallel resistance. The input to the switches is from the same pin. I'm curious if its simply 12v. I need to draw it.

Those diagrams suck. I have a hard copy (the real deal) here...lemme take a look...

Ah hah! This is why we are confused. The clutch switch looks like it's in the transmission, and yes, it is hooked to the neutral switch. Looks like it has the same function - to signal the ECU when the clutch is depressed. I guess the ECU gets the same signal when the tranny is in neutral as well. Makes sense.

What you are looking to bypass is actually called the starter interlock switch (the one on the clutch pedal under the dash). At least it is in my manual. It is actually wired in before the starter. That's the one you're talking about, right?

If so, hook those wires (black/red, black/blue, correct?) to the relay power circuit. Use the neutral switch ECM wire as your trigger ground, and your button for trigger power (to a 12v source). That should get you the results you are looking for.

[PoisonDrop]

Haha! You must have posted while I was writing my LONG response!

LOL!

[PoisonDrop]

But then you lost the ability to hook into the neutral switch.

That looks rather redundant now...

[Inodoro Pereyra]

Ryan: you don't need a relay at all. The clutch switch does not handle high current.
Just wire your switch in parallel with the clutch switch, and you're done.

Yes, as long as your switch is high current as well. But then you lost the ability to hook into the neutral switch.

I really don't know what you guys are talking about.
If what you want is to bypass the clutch switch to be able to start the car without stepping on the clutch pedal, you only need to hook up a switch in parallel to the clutch switch. When you're pressing that switch, it's exactly like you were pressing the clutch, and when you're not pressing it, the clutch switch works as if the bypass switch didn't exist.
The switch doesn't need to be high current at all, the clutch switch isn't. That switch only provides a ground reference to the ECU.
Besides that, I don't know why you want to involve the neutral switch. If you try to start the car while not in neutral, without pressing the clutch, it will jump forward (or backwards) whether you bypassed the switches or not.

That is, unless I'm completely misreading this whole thread, in which case I apologize.

[PoisonDrop]

If you try to start the car while not in neutral, without pressing the clutch, it will jump forward (or backwards) whether you bypassed the switches or not.

That's why he wants to include the neutral switch, so that can't happen.

[Inodoro Pereyra]

If you try to start the car while not in neutral, without pressing the clutch, it will jump forward (or backwards) whether you bypassed the switches or not.

That's why he wants to include the neutral switch, so that can't happen.

I think you're confused. The neutral switch only tells the ECU the transmission is in neutral, it doesn't disengage the transmission.
You can include the neutral switch all you want, and when you try to start the car in gear without stepping on the clutch, the car will still jump forward or backwards, depending on the gear you're on, or the engine will stall if the E brake is engaged.

[Ryan]

If you try to start the car while not in neutral, without pressing the clutch, it will jump forward (or backwards) whether you bypassed the switches or not.

That's why he wants to include the neutral switch, so that can't happen.

I think you're confused. The neutral switch only tells the ECU the transmission is in neutral, it doesn't disengage the transmission.
You can include the neutral switch all you want, and when you try to start the car in gear without stepping on the clutch, the car will still jump forward or backwards, depending on the gear you're on, or the engine will stall if the E brake is engaged.

This is exactly what I'm trying to prevent. If the car is NOT in neutral, the relay will be open (no signal from neutral switch), and the new button will not work.

I could just run a parallel loop around the clutch switch. That is very simple and I would not have posted this topic if thats all I wanted.

But, in that loop I want to add a relay to act as an interrupter, so the new button cannot function if the car is in gear.

Its an 'extra' feature.

And starters do walk cars away, even with ebrakes on. I know a few people who can verify.