He told the Mechanic if the wiper's problem comes from the wiper motor.

[Jit833]

1) He told the Mechanic if the wiper's problem comes from the wiper motor or something else/some other things.

2) I do not know what is the cause of the malfunction in/of the wiper/ I do not know what is causing the
malfunction in/of the wiper. ( Which sentence is more appropriate? Should I use in or of ?).

3) The wiper's motor is still functioning properly. ( Is there any other word that can be used as a substitute for the word properly in the sentence?).

*Hope somebody can help me correct the above sentences if they are written incorrectly. Thanks

 

[5jj]

1) He asked the Mechanic whether the wiper problem came from the wiper motor or something else.
2) I do not know what [STRIKE]is[/STRIKE] the cause of the malfunction in the wiper is/ I do not know what is causing the malfunction in the wiper.
3) The wiper motor is still functioning properly/as it should.