What you have there is a 2pole double throw switch (DPDT), all you needed was single pole double throw (STDP). Just use one side of the sw. Also, with dc volts it is always better to switch the - not the +. Switch plus is like pushing a loaded wheel barrel up an incline. This creates a greater in-rush current which fused don't like. On each relay coil connection attach the + wire and take the - from the switch to the other side of the coil. I'll be checking this thread through out the day.