So I have a 2002 Acura TL type s and my drivers side headlight is completely off except for parking and signal. I brought it to a mechanic because I couldn’t figure it out and I’m not sure what they did but they said it had something to do with the ground and so they zip tied the fog lights to the chassis and it worked for like an hour or so then it went out. So for a fact I know it works it’s just something is up. Loose connection? For the low beam I can’t seem to find the ballast and igniter kit I’ve seen on some posts so if you guys could give links for that that would be great, thanks!

 

Disconnect the battery to body ground hit it with some sand paper hit the connector with some sand paper and put it all back together. Spray with clear coat. I had the same issue and did the big 3 upgrade wire. Went away lights are super bright now.

 

Good advice in the above post. If that doesn't work and you dont have any loose or frayed wires you've got to replace some parts.
If you are looking for the ballast and ignitor to test or replace you'll have to remove the front bumper and bracket then remove your headlight assembly. Flip it upside down and you'll be able to unscrew the ballast from the housing. This is most likely your problem.
These cars were build in the early days of HID technology, they are susceptible to moisture damage. I've replaced quite a few of these for myself, friends, and customers over the years.
And before you buy any new parts, while you have everything apart swap the bulb, ballast, and ignitor from your working passenger side headlight and test if they work on the drivers side to rule out a wiring issue.

 

Hold on, can you walk me on the sanding the parts really quick, I don’t quite get where to start off on there