dodgy headlights
 

I hope someone can help me. My 2004 xc90 got a problem with the nearside headlight intermittendly going on and off while driving. Its got the fancy expensive headlights on, but other than the one side hardly wanting to work, the brightness on them is very poor, not sure why, maybe the ballast. Lenses isnt very clear but the highbeam is very good telling me the lenses is ok. I would like to replace them with the normal healight that take the h7 bulbs i think it is as the are like more than half the price. Can i do this? Is it a straight swap or is the plug etc on the back different?