I have replaced the alternator and had the battery tested ok. 11.8 volts @ the battery with car running or not. That is why i replaced the alternator. Reassembled car and started with the same problem. Battey light on and no power steering. Any help?

 

what model mini do you have?? If it is a Cooper S, You may have a bad crank pulley. If the inside of the pulley has seperated from the outside then belt will slip and cause similar complaints to what you are describing.