cooling fans

hi all ,has anyone got any idea how i can wire up the twin fans off my disco 200tdi onto my 90 using the switch off the engine ,
i have an idea on how to but not a 100% it will work

put a live feed to fans then send an earth to one side of temp switch and from the other to the chassis , so as it gets hot it makes the earth and fans come on can someone tell me if that would work or is it the other way around

basically thats it - but do it via a relay and a couple of fuses.

cheers mate will do that if i can work it out ,you have only gone and confussed the matter

hope yu can read this.