Headlight assembly travel adjustment

[vagent]

What determines the amount of travel when the headlights are activated?  I just completed replacement of bushings and actuator arm on the left headlight (driver side).  Now the left headlight,  the one I worked on, opens right much further than the right.   (And,  I failed to check the aiming before tackling the repair so I don't know if I've changed things or if they are like they were before  :-(  )  I expected some headlight adjustment, but this appears to go beyond headlight adjustment screws capabilities.  And it is obvious that the left headlight assembly opens further than the right.  

 

Is this adjustable by the manual rotor for the motor?  Is it adjustable by where the actuator arm is sitting when you engage the large gear with the motor gear when reassembling the components?  Help would be appreciated.

 

Thanks in advance.

 

Vagent

[Ronnie]

Welcome to the forum!

 

There is no adjustment on how far the door opens. Both doors should open the same amount and they should consistently stop in the same location. That is determined by where the crankarm's rubber bumper strikes the stop made into the cam shaped part of the frame the motor/gearbox bolts to. You can see what I mean in the photo below.  If both doors aren't opening the same amount there is a problem.

 

There is an upstop screw that needs to be adjusted after you have installed the headlight doors. The purpose of the upstop is to keep the slack out of the linkage in order to keep the headlight assembly from vibrating and bouncing around once the door is fully open.  If you try to use it to stop the travel of the headlight door it will break the plastic nut that it screws in to.  Once you have the upstop screw adjusted properly you aim the headlights with the adjustment screws on the headlamps just like you would with any other GM car.

 

[Ronnie]

Just a though about the door opening higher on one side... did you install a rubber bumper on the crankarm?  If not that might account for the headlight opening a little more before the crankarm hits the stop.

[vagent]

Thanks for the prompt reply, Ronnie.  I was "out of pocket" and couldn't reply until now.  So it's the rotating arm with the rubber bumper that determines the travel?  I do have the rubber bumper on.  

Does the resistance encountered when the rotating arm rubber bumper hits the stop cause the motor to sense the resistance and stop running?  Makes sense.  Thanks again.

[Ronnie]

1 hour ago, vagent said:

Does the resistance encountered when the rotating arm rubber bumper hits the stop cause the motor to sense the resistance and stop running?  Makes sense. 

Yes, there is a headlight door control module that senses the extra current draw when the crankarm  hits the stop and shuts off the power going to the motor. Are you able to easily lift the other door up to the same height as the one you just overhauled?  If so it probably needs to be overhauled too.  There normally is a little slack in the linkage but there shouldn't be enough to make a difference in how high the doors open.