thanks for your input .i will try to answer your questions1.when pump is out of car i put it across 12v battery it spins and pumps fine ,in car it is dead!
2.it parks randomly.
i think i agree with you that the motor is the problem but iwould still like to know if there is a relay or control box that would be easier/cheaper to change!any ideas as to who/how to find out as haynes manual/not very helpful.
also does anyone know if w123 w124 motors are interchangable?
thanks
hamish