With out the pedal pressed:
test the wire with the Ignition OFF
test the wire with the Ignition ON
test the wire with the key in the start position
With the pedal pressed;
test the wire with the Ignition OFF
test the wire with the Ignition ON
test the wire with the key in the start postition
With this information for every wire at the switch, determining what type of the clutch switching system you have will be easy.
DIRECT FEED
The simplest type of system to test and bypass is the "Direct Feed" system. This circuit simply interrupts the +12V signal starter wire from the ignition switch to the starter solenoid. There are 2 wires in this circuit, the "key side" wire which goes from the clutch pedal to the Ignition switch, and the "solenoid side" which goes from the clutch switch to the starter motor. When the key is turned to the start position without pressing the pedal, you will test 12V only on one of the wires at the clutch switch, this is the key side. When the pedal is pressed down, and the key is in the crank position, the other wire will also read 12 volts; this is the solenoid side wire. To confirm you have a direct feed clutch switch, hot wire the "solenoid side" wire with a fused +12 volts and the starter motor will crank. Connect the starter output from the remote starter to solenoid side wire.
NOTE: In the next two systems a Relay in the vehicle interrupts the start wire between the Ignition switch and the starter motor. With the key in the start position, and the clutch pedal pressed, the relay energizes and allows the start signal to reach the starter motor. In these systems a wires from the clutch triggers the relay, when the pedal is pressed. There will be another wire at the clutch switch that supplies the signal to the trigger wire{either postive or negative, depending on the system}
NEGATIVE:
In a Negative system, when the clutch is pressed: a negative signal is sent to the relay, the relay energizes, when the key is turned to the start position the 12volts from the starter wire is allowed to pass through the relay and to the starter motor. One of the wires at the clutch will test as negative, this is the supply wire. The relay's negative trigger wire will only show negative when the pedal is pressed{some vehicle's also require the ignition system to be powered}. To confirm you have a Negative system, hot wire the negative trigger wire by jumping it to a ground source with your fused test jumper. You should now be able to turn the key to the start postition and engage the start motor without pressing in the clutch pedal. If there is nothing else connected to the Ground OUt When Running{G.O}wire from the remote start module, the G.O. wire should be strong enough to trigger the vehicle's clutch relay. If there are other devices or modules connected to the G.O. wire a relay{and diodes} may have to be added to strengthen the negative current going to the clutch bypass.
POSITIVE:
Very similiar to the negative system, except that the vehicles clutch relay is trigger by 12 volts, instead of a negative signal. In a positive system, when the clutch is pressed: a positive{12 volts} signal is sent to the relay, the relay energizes, when the key is turned to the start position the 12 volts from the start wire is allowed to pass through the relay and to the starter motor. One of the wires at the clutch will test as 12 volts, this is the supply wire. The relay's positive trigger wire will only show positive when the pedal is pressed{Some vehicles also require the Ignition system to be powered}. To confirm you have Positive system, hot wire the positive trigger wire by jumping it to a 12 volt source with your fused test jumper. you should now be able to turn the key to the start position and engage the start motor, without pressing in the clutch pedal. A relay is needed to send 12 volts to the trigger wire from the start module during start attempts.
Normally Closed(N/C):
NOTE:There are different types of this system used by various vehicle manufacturers: the following is used to illustrate how these systems work in general.
A relay is also used in these types of systems to interrupt the starter wire. In the previous two examples, the clutch was bypassed by engaging the clutch relay; with this system you bypass the clutch by preventing the clutch relay from engaging. When the Ignition key is turned to the start position the relay energizes and interrupts the start wire, when the pedal is not pressed. When the Ignition key is turned to the start position, and the pedal is pressed, the relay does not energize and the start signal reaches the starter motor.
In a N/C system the supply wire is connected to the relay's trigger wire at rest (pedal not pressed). When the pedal is pressed, the connection is broken between the supply wire and the relay's trigger wire (this disengages the relay). To verify that you have a N/C system, disconnect the clutch switch and the vehicle should start without the clutch pedal being pressed. When you test the trigger wire with you logic probe, the trigger wire will test as 12 volts or negative when the pedal is not pressed, it should read as an open circuit(or float) when the pedal is pressed
NOTE:
Your probe may also show feed back from the end of the circuit. The Polarity of the trigger wire does not matter in this system, since all you need to do in order to bypass it is to use a relay to interrupt it during remote starts.
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