This cable is used to connect AUX radios for receive only audio, to "C-RX" on J508 (Which is power port when the device isnt used with the complete VRC series radio mounts) of the AM-1780/VRC
This is an excellent place to insert IPOD, external audio type sources.
- D - Switched +V, this pin goes +Voltage when the AM-1780/VRC is turned on
- H - Receive Audio (Speaker)
- K - Receive Audio (Fixed Volume)