# Multipurpose Equipment

The multipurpose equipment provides a junction location for airframe and engine systems. It consists of the relay panel.

## Relay panel

The relay panel serves as the mounting bracket for the IDLE/FLY, START, IGNITION, XOT HOT, XOP LOW, FUEL LOW, CRANK, and FANS relays, a terminal block rail, the connector to the engine and airframe systems, and the Engine Control Unit (ECU) test connector. It is located on the avionics shelf.

## Operation

Refer to [Engine Control](https://bell-505-guide.gitbook.io/bell-505-maintenance-guide/system-descriptions/power-plant-systems/engine-control) for the operation of the IDLE/FLY, START, XOT HOT, XOP LOW, FUEL LOW, and CRANK relays.

Refer to [Ignition](https://bell-505-guide.gitbook.io/bell-505-maintenance-guide/system-descriptions/power-plant-systems/ignition) for the operation of the IGNITION relay.

Refer to [Avionics Fans](https://bell-505-guide.gitbook.io/bell-505-maintenance-guide/airframe-systems/environmental-control/avionics-fans#operation) for the operation of the FANS relay.

Refer to [Transmission Indicating](https://bell-505-guide.gitbook.io/bell-505-maintenance-guide/main-rotor-drive/main-rotor-drive-indicating#transmission-indicating), [Freewheel Indicating](https://bell-505-guide.gitbook.io/bell-505-maintenance-guide/main-rotor-drive/main-rotor-drive-indicating#freewheel-indicating), and [Oil Indicating](https://bell-505-guide.gitbook.io/bell-505-maintenance-guide/power-plant-systems/oil#oil-indicating)  for the operation of the terminal block rail.

Refer to [Engine Control](https://bell-505-guide.gitbook.io/bell-505-maintenance-guide/system-descriptions/power-plant-systems/engine-control) for the operation of the ECU test connector.