with no a/c condenser fan the high side head pressure will go sky high. the engine will have trouble turning the compresser at those psi and engine speed will drop. try hitting the fan motor and see if it starts to spin. if so the brushes in the motor are bad and it will need to be replaced.if it doesnt spin then see if it is getting power may be a blown fuse or open wire. normal high side psi should be around 150 - 185 depending on outside temp.