Sir Scousebil . . . . .
Use 4 1.5 batteries resting in a squared trough to hold in linear alignment and two pieces of bare ended tips of hook up wire.
Have assistant hold wire ends to + and - batts extreme ends and you place the two free ends of the two wires to the relay coil and then you will be able do an initial combined hearing / feeling of the coil responding to the applied power to the relay..
If clickee-clickee . . . .feelee-feelee . . .THEN do an electrical test of the contacts action by using clip leads between the relay contact pins and the use of the LOW ohms scale of a DVM. The relay contacts should short out each time you activate its coil electrically.
HOWEVER . . . . I think that you are going to be having a good relay anyhow.
We COULD use a closeup photo of the relay with its markups on its top side and bottom side.
Additionally and MORE importantly, a full frame . . .squared off . . .in focus . . .well lit . . .closeup photo of both sides of the PCB to evaluate and see just exactly what you have there.
Also, why would there be 2 relays with one not connected to anything ?
I can't see the actual mounting on of an unused relay, instead of just unpopulated holes . . . . .by the PENNY PINCHER manuf's, but, if so, you just might have yourself a virgin relay there.
73's de Edd