How to locate where to drill the hole for mounting the housing in the side sliding door.
As far as the left to right alignment it is most important to know where the inside door edge lands when the door is shut.
You can locate this by closing the sliding door and
from the inside pull back the rubber weather strip to gain access to see the door edge.
Next open the door to view your line indicating where the door’s edge is on the "C" pillar.
With the door closed use your marker to draw a short line on the "C" pillar indicating the door edge.
Once you know where the door edge is you can align the strike plate to fit between the marked line and the outside edge of the “C” pillar.
It should be approximately 1/2” from the line’s edge.
Once you find a suitable spot trace the inside square opening and both mounting holes.
Then on the “C” Pillar mark the distance from line to center of hole using paper or the strike plate bracket itself as a template.
Next almost completely shut the side door and use a straight edge to mark the top of the square hole position on to the side of the sliding door.
Now apply the template to the sliding door’s edge to find the center by aligning the mark on the template from the edge of the door as shown.
The alignment of the bolt striking into the strike plate should now be spot-on after you install your housing.