Okay so I have a 2000 blazer that I just bought and installed spec d tuning headlights in but only the passenger side lights are working and I only have a tiny amount of light being produced by the driver side lights

 

Is the dimmed driver's side light the intensity it would be if it was in daytime running light (DRL) mode? If so, perhaps that could be a clue to where to look.

 

Yup, these things have fuses for individual side headlights, and against most everything that I learned about electricity, with a bad fuse it will still get some voltage and you will get some Odd light operation. Figured I had a bad ground somewhere with what my symptoms were, but when I finally gave up and had my shop look into it, was a simple fix with a new fuse. I had the issue with my projector halogens and the stock assemblies.