KF56 - Check AC Pressure Switch (ACPSW)

- Key "OFF".

- Low Fan Control (LFC) and High Fan Control (HFC) relays disconnected.

- Reconnect additional fan relay.

- Disconnect A/C Pressure Switch (ACPSW) (also known as Refrigerant Containment / Fan Function Switch).

- Key "ON".

- Does the fan run?

Yes -- Key "OFF". Go to KF57. KF57 - Check Additional Relay For Short To Ground

No -- Key "OFF". Reconnect HFC and LFC relays. Go to Heating and AC to check ACPSW operation.