I had something similar and removed the door lock motor.  It's not too
difficult.  It's behind the door panel and under the knob that moves up and
down when you lock and unlock the door.  Then I took the motor apart.
Inside is a slider contact - a narrow strip of copper and which has 2 small
springs that push it against the contact strip.  They are very small.
(maybe 2mm diam. and 4 - 5 mm long).  Well the springs had rusted through.
I found a spring at Home Depot that worked perfectly, cut it to size and the
motor works again!

While there, I cleaned everything and lubricated the mechanism with light
weight grease.  Vaseline actually.

Good luck

Rich
90 Westy