Clutch switch wiring 12v or gnd?
06-21-2022 | 08:09 AM
#2
There are actually two switches on the clutch pedal - one for starter enable and the other for cruise control disable.
The starter enable switch is powered only when the key is in the start position via the purple/white wire and outputs to the starter relay coil via the dark green wire. The other side of the starter relay coil is ground by the BCM VATS circuit to prevent the car from starting when VATS doesn't see the correct key resistor pellet. This circuit would not be appropriate for your needs.
The cruise control disable switch has ignition switched power input on a pink wire and output to the cruise control module via the brake switch. It is closed in the resting position allowing power to flow to the cruise control module as a signal that cruise can be enabled. When either the clutch or brake is depressed, the corresponding switch opens, breaking the power supply to the cruise control module and signaling it to turn off. You could only use this switch if you add a relay to reverse the output conditions. You do that by adding a standard automotive (Bosch style) relay with pin 86 tapped into the brown/white wire from the clutch switch, pin 85 connected to ground, pin 30 connected to ignition switched power, and pin 87A as the power output to your device. Leave pin 87 disconnected but insulate it to prevent shorts. During normal operation, the relay will be energized and directing its input power to pin 87 which you've left unused. When the clutch is depressed, the power to the relay coil is interrupted causing it to return to its rest state which switches the power from pin 87 to pin 87A where you've connected your device. In other words, pin 87A will have power only when the ignition is on and the clutch is depressed.
The starter enable switch is powered only when the key is in the start position via the purple/white wire and outputs to the starter relay coil via the dark green wire. The other side of the starter relay coil is ground by the BCM VATS circuit to prevent the car from starting when VATS doesn't see the correct key resistor pellet. This circuit would not be appropriate for your needs.
The cruise control disable switch has ignition switched power input on a pink wire and output to the cruise control module via the brake switch. It is closed in the resting position allowing power to flow to the cruise control module as a signal that cruise can be enabled. When either the clutch or brake is depressed, the corresponding switch opens, breaking the power supply to the cruise control module and signaling it to turn off. You could only use this switch if you add a relay to reverse the output conditions. You do that by adding a standard automotive (Bosch style) relay with pin 86 tapped into the brown/white wire from the clutch switch, pin 85 connected to ground, pin 30 connected to ignition switched power, and pin 87A as the power output to your device. Leave pin 87 disconnected but insulate it to prevent shorts. During normal operation, the relay will be energized and directing its input power to pin 87 which you've left unused. When the clutch is depressed, the power to the relay coil is interrupted causing it to return to its rest state which switches the power from pin 87 to pin 87A where you've connected your device. In other words, pin 87A will have power only when the ignition is on and the clutch is depressed.
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CFM (06-21-2022)