well, I think i've still got some juice spare from the power supply so I may add some yellows laters on..

Can I just clarify that I would need the voltage regulater/capacitor and not just resistors to run the fan from the 24v?

Thanks again to everyone that helped and in particular Bill.

J_R

 

For the fan I listed 3 options, all would work.

A high wattage resistor in series with the fan.

Two fans in series.

A simple regulator (that will require some small capacitors) to drop the 24VDC to 12VDC.

I think you have theory down now.