What is the correct output to use on contact terminal 85 of a relay when integrating the clutch switch for a remote start in a manual transmission vehicle?

Using the negative starter output on contact terminal 85 of a relay when integrating the clutch switch for a remote start in a manual transmission vehicle is appropriate for several reasons.

In a manual transmission vehicle setup, the clutch switch serves as a safety mechanism that ensures the vehicle can only be started when the clutch pedal is depressed. By employing the negative starter output, the relay can be activated when the clutch switch is closed. This means that when the clutch pedal is pressed, it will complete the circuit, allowing the relay to engage and, in turn, enabling the starter circuit to function.

This approach effectively isolates the starter from unintended activation while safeguarding against potential safety issues that could arise from starting the vehicle while in gear. It ensures that the remote start function will only be operational under the necessary conditions, maintaining the vehicle's safety.

The other options introduce different voltage levels or grounding points that wouldn't effectively control the relay under the specific requirements of a remote start integration with a manual transmission and are therefore less suitable for this application.