Thanks for your reply.
The 5V I have wired into the terminal is coming from an AC mobile phone charger.
The point of using a 5V input ATM with the solderless breadboard and leds was to simulate a solenoid setup as I want to test that the software I am writing is working correctly.
ATM non of the provided phython, the c self test program or any of the scripts/code I have written work with the scenario I have described in my earlier post.
I am going to pick up another 24VAC transformer and wire up a spare solenoid to do the testing.