Thermo fan issues vx v8

[vxss392]

Hi, am in need a abit of advice or can someone point me in the right direction. I have a cooling fan issue in my 02 vx ss.. the passenger side fan blade spat off the fan motor yesterday so i replaced the the whole fan assembly with a second hand genuine one, seem to work fine when tested but then it spat the same blade not even five minutes after installing while driving. I have just had the wiring and a new plug to replace the burn out old genuine plug a month back by a local auto lekky. So I'm thinking maybe its wired wrong and the motor might be spinning backwards and throwing the blade or its just bad luck that they both done it also is the vx v8 radiator fan assembly the same as the v6. Anybody help or had the same issue? cheers