its the bottom black screw that adjusts height, my top silver ones dont do anything

 

On mine its the silver one that adjusted the hight the black one adjusts the left or right. Here's pic of the adjuster for the left/right for the low beam.

 

Oops, sorry wrong pic. Thats the high beam one left/right adjustor. This is the low beam left/right adjustor and this silver adjustor is the one that did the hight on mine. Had to remove the battery to get to it. Not the most spacious engine bay.

 

That's really weird, my silver ones don't do Jack lol, the black ones adjust height on mine. Why could that be? Mines a 92, what's yours guys?