2001 radiator cooling fans

[armagh]

I am assuming the fans should come an when the engine heats up especiall at idle.
I have been stopped in traffic and had the gauge goto nearly 3/4
When I run the engine at home for a wile neither fan comes on.

I have connected a 12v supply to each fan and theu do work

Checked the 2 fuses they are ok
the 3 relays all clicked when I applied 12 volts to the appropiate connectors.

That is as far as I have gotten can anyone point me in another direction

Thanks