Many of today's 2-way alarms include a remote-start feature which usually carry a warning label for use with Automatic transmissions only.
However we are fortunate in that our manual transmission NSX's have a neutral switch upon which we can capitalize to ensure safe starting that will only engage when said transmission is indeed in neutral.
Disclaimer: Undertake this at your own risk. I am not responsible for any issues or damage caused to your vehicle or others caused by use of this circuit or any problems associated with mis-wiring. Unless you possess rudimentary electronics knowledge I suggest you refrain from undertaking this directly, but consult a professional.
Here's how you can achieve this:
1. Wire up the starter cut relay that comes with your after-market alarm per the instructions in your alarm's installation 'manual - it should be like the part of the cct in the top left of the schematic. You must cut the black/white wire (the starter feed) from the ignition switch and connect the common & N/C contacts of the relay across the two ends of the black/white wire. The power for the relay coil comes from connection to the ignition wire, while the "ground" signal to energize the relay comes from the alarm module.
Again, this is all standard wiring per your install manual so far.
2. Wire up a second relay for your clutch/neutral switch interlock circuit. This is now a new custom feature and your alarm manual won't have details of this, or the include the additional parts required.
Connect the Power coil connection of the relay to the "start" O/P from your alarm and then run a wire back to your OEM ECU for the ground enable side of the coil - this wire will tap onto the Lt. Green wire that goes to pin B7 at the ECU (this is where the neutral switch terminates).
Now, connect the Common & N/O contacts across the clutch pedal switch by tapping onto the Black/Green & Black/Yellow wires.
Finally, connect a diode between the Black/White wire of the starter cct to the connection of the remote start feed from the alarm (that also connects to the power side of the relay coil). Ensure the diode is connected in the correct orientation, as per the diagram - the Cathode (end with the bar) connects to the Black/White starter wire, while the Anode (opposite end to that with the bar) connects to the junction of the O/P for the Remote Start from the alarm brain and the power side of the relay coil. Also be sure to connect the cathode of the diode to the correct side of the "cut" Black/White starter wire - should be the one that is no longer directly connected to the ignition switch.
How it works: When you press the remote start on the remote key-fob, the relay 2 will energize only if the car is in neutral and the neutral switch completes the cct - the relay must energize in order to close the contacts shorting out the clutch switch which normally inhibits the OEM starter cct. So it performs two functions in one - inhibits the starter unless the car is in neutral and bypasses the clutch switch, so the pedal does not have to be depressed. The diode is there to prevent the relay energizing during a "normal" ignition key switch start, thereby still requiring the clutch pedal to be depressed during this type of starting.
Depending on what brand of alarm you have purchased, there are several means of preventing over-cranking - be sure to follow the instructions in your manual for this. With my Crimestopper alarm, I found the "tachless" voltage detect method works perfectly, eliminating the requirement to wire up to the tach. My friend's Autopage system also worked with this method, although we had to mess with the settings to get it just right (his turbo system cranks a little longer before firing)
Parts required:
http://www.radioshack.com/product.a..._name=CTLG_011_002_013_000&product_id=275-226
http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=276-1103
Here's the location of the wire from the neutral switch that you tap into - it's light green and plug reference B7 in the ECU - it's ~ in the middle on the front row of the second plug down.
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However we are fortunate in that our manual transmission NSX's have a neutral switch upon which we can capitalize to ensure safe starting that will only engage when said transmission is indeed in neutral.
Disclaimer: Undertake this at your own risk. I am not responsible for any issues or damage caused to your vehicle or others caused by use of this circuit or any problems associated with mis-wiring. Unless you possess rudimentary electronics knowledge I suggest you refrain from undertaking this directly, but consult a professional.
Here's how you can achieve this:
1. Wire up the starter cut relay that comes with your after-market alarm per the instructions in your alarm's installation 'manual - it should be like the part of the cct in the top left of the schematic. You must cut the black/white wire (the starter feed) from the ignition switch and connect the common & N/C contacts of the relay across the two ends of the black/white wire. The power for the relay coil comes from connection to the ignition wire, while the "ground" signal to energize the relay comes from the alarm module.
Again, this is all standard wiring per your install manual so far.
2. Wire up a second relay for your clutch/neutral switch interlock circuit. This is now a new custom feature and your alarm manual won't have details of this, or the include the additional parts required.
Connect the Power coil connection of the relay to the "start" O/P from your alarm and then run a wire back to your OEM ECU for the ground enable side of the coil - this wire will tap onto the Lt. Green wire that goes to pin B7 at the ECU (this is where the neutral switch terminates).
Now, connect the Common & N/O contacts across the clutch pedal switch by tapping onto the Black/Green & Black/Yellow wires.
Finally, connect a diode between the Black/White wire of the starter cct to the connection of the remote start feed from the alarm (that also connects to the power side of the relay coil). Ensure the diode is connected in the correct orientation, as per the diagram - the Cathode (end with the bar) connects to the Black/White starter wire, while the Anode (opposite end to that with the bar) connects to the junction of the O/P for the Remote Start from the alarm brain and the power side of the relay coil. Also be sure to connect the cathode of the diode to the correct side of the "cut" Black/White starter wire - should be the one that is no longer directly connected to the ignition switch.
How it works: When you press the remote start on the remote key-fob, the relay 2 will energize only if the car is in neutral and the neutral switch completes the cct - the relay must energize in order to close the contacts shorting out the clutch switch which normally inhibits the OEM starter cct. So it performs two functions in one - inhibits the starter unless the car is in neutral and bypasses the clutch switch, so the pedal does not have to be depressed. The diode is there to prevent the relay energizing during a "normal" ignition key switch start, thereby still requiring the clutch pedal to be depressed during this type of starting.
Depending on what brand of alarm you have purchased, there are several means of preventing over-cranking - be sure to follow the instructions in your manual for this. With my Crimestopper alarm, I found the "tachless" voltage detect method works perfectly, eliminating the requirement to wire up to the tach. My friend's Autopage system also worked with this method, although we had to mess with the settings to get it just right (his turbo system cranks a little longer before firing)
Parts required:
http://www.radioshack.com/product.a..._name=CTLG_011_002_013_000&product_id=275-226
http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=276-1103
Here's the location of the wire from the neutral switch that you tap into - it's light green and plug reference B7 in the ECU - it's ~ in the middle on the front row of the second plug down.
.
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