My left head lamp clicks as it opens and closes. Sometimes it does not open all the way. What should I do to fix it.

It is time consuming,  and a tad fussy. The three little plastic pucks in the mechanism need to be replaced. The light will eventually stop opening but make a bunch of noise. If you are not mechanically inclined, let someone else fix it. The entire assembly will need to be taken out of the car. 

As Mark says it is time consuming but it is a relatively easy project.  Years ago replaced the gears on both headlights on "The Beast" - the first one took longer than the second one.  By now there are probably YouTube videos out there that will walk you thru the process.

Thank You I seen where you can get metal replacements gears.

Yep, that's what I used.  Sorry I don't remember where I got them.

Check out the Tech Section at Corvette Central. Excellent video and parts from them as well.

Check out mirrock corvettes video on head light motor repair and get educated prior to completing the job. No need for metal gear waste of $$. They are on YouTube and explain rebuild 

I agree on metal vs plastic gears. When I replaced the little plastic pucks in the housing, the gears were in very good condition. I cleaned and added a good quality graphite grease and replaced them. Very smooth and precise movements. If the microswitches are operating correctly for start and stop, the gears take no abuse. Clean and lubricate. Should be sufficient. 

I did mine last winter passengers side was easy, drivers side was a little more difficult. Plastic gears are worn, you will see when you disassemble. 

When I bought my first C4 the right lamp quit working, bought a new motor (expensive) and replaced it. When the other one quit working I had watched Mirrock’s YouTube video (qhttps://youtu.be/RBCrYvslp_o?si=-Bn0e_3K5QdNPV-R) and rebuilt it. That was four years ago and it’s still working. Have fun on your C4!