Goodaye guys. I have a RPi running OpenLec as my media player down my farm. I have no internet access so everything is dumped on the 2TB USB HDD.

The RPi is powered on full time running off the solar charged batteries via a buck inverter to get the 5vDC with the USB HDD powered off a powered hub again, powered all the time and everything has been running flawlessly until about a month ago when the HDD come to the end of it's life after running for 3 years.

Something I sort of expected considering they aren't designed to spin non stop all there life.

My question is can I put a switch in the USB HDD red supply wire so when not in use, between visits, I can power down the HDD?.

The switch will be a relay actually that comes on when the radio is on. The Radio has a power wire and standby supply going to it. The standby so the radio doesn't loose it's memory but it is this memory supply that keeps the RPi powered as well.

What I want is to continue using the RPi powered all the time as I have had no SD card corruption problems doing it this way but a simple way the HDD powers down when I'm not there.

Is it as simple as killing the red wire in the USB cable going to the HDD rather than physically unplugging the HDD that I have been doing since replacing it?.