hi, i have recently purchased a 1993 sl 300

the central locking wasn,t working,
i researched the forums and when i dismantled the pump i found the motor was fried.
i replaced the motor and now when i connect the pump up it runs for several seconds and then blows the fuse, motor gets very hot

i have tried running the motor in both directions but no difference

should there be a cut off within the unit?

please help