1992 240sx Hatch - intermitent windshield wipers and power door locks not working

Ok,

I have been doing some research and cannot pin out what is happening with these two problems however I believe they could be related

When I bought the car the power door locks and the intermitent wipers worked just fine

after a year the wipers would not park properly so I replaced the amplifier and the motor from a scrap yard and it fixed the problem

a little bit after the door locks stopped working ( the car does not have a switch for the door locks, when you lock the drivers door it would lock the passenger, or when I pressed the lock button on the key fob it would lock)

A relay still clicks when you press the button and the lights flash but that is all ( alarm engages but doors do nothing )

maybe a week or two after this the intermitent wipers stopped working, they work on meduim speed and fast, and they do not wipe when you use the windshield washer sprayers ( sprays but doesnt wipe )

I believe this could be related to the Timing control unit but am not sure and have not inspected it

Does anyone have any suggestions

Thanks,

          Jay