okay i get these codes.
521 = PSP Failed Open, The switch must be closed for the KOEO and ER test. During ER test, the steering must be turned approx 1/2 turn. Can be caused by disconnected or faulty switch, or failure to turn steering during test.

794 = FC4 Output Check Fail, Electro Drive fan 4 output is faulty. Can be caused by open circuit, or shorted to Ground, +12V.

791 = FC1 Output Check Fail, Electro Drive fan 1 output is faulty. Can be caused by open circuit, or shorted to Ground, +12V.

793 = FC3 Output Check Fail, Electro Drive fan 3 output is faulty. Can be caused by open circuit, or shorted to Ground, +12V.

792 = FC2 Output Check Fail, Electro Drive fan 2 output is faulty. Can be caused by open circuit, or shorted to Ground, +12V.

777 = Drivers side Cooling Fan not operating, The Fan motor is not drawing current from battery when switched on by EEC Module during self test

778 = Passenger side Cooling Fan not operating, The Fan motor is not drawing current from battery when switched on by EEC Module during self test.
Now i have tested the fans straight to the battery and they work superbly, but they just don't turn on i have checked the relays and cleaned the earth terminals.

Somebody please help.

your fan has died? or check your fuses/relays maybe.

if your fan has died, go get a second hand one for the passenger side and take the old one out (clipped in) and put the other one in.. very easy job

ta for trying, check other post