door locks?

1998 v70 wagon doors lock but olny the driver side opens? i opend the rear door panel i see the lock locking but it woint open? i see a whit thing turning but its not ingageing to unlock? the olny unlocking is the drivers door? please can some one help the owner befor me took it to volvo but theay said it was something electrical? if it was somrthing like that i thought that it would not make a noise to open? or nothing would trun