Volvo: electrical demon, high beams, inner fender

Question
I have a 1989 740 turbo wagon.  It has the replaceable sealed beam headlight
units and it is with these that I have a problem.  For some reason, when I turn
on the high beams, the engine stalls.  It stops right away, as if I have
activated a kill switch.  I don't believe it is the alternator.  As well, the left
bank of lights is poorly illuminated, as though starving for power.  Aside from
this bizarre twist the car has been running fine.  The lights were all just
replaced (by me) and were working fine.  I don't even know were to begin.  
Help me Obi Wan Kenobe, you're my only hope.  Seriously though, I hope you
can offer some insight.  Thank you muchly.    Aaron.

Answer
Aaron,
Bad ground cause many problems as you have described. Go over the areas that you have touched wires and make sure that the ground wires are all good clean and tight. Check also that the covering of the wires has not come off and wires are shorting out. There are light ground wires left and right inside the inner fender behind the lights. Test the chargeing system and see that it is working properly. Make sure that the alt is grounded with a wire.