Dim HID Xenon headlamps? Projector bowls are burnt. I fixed mine.
 

The HID low beam headlight output on my 2009 Acura MDX got extremely poor. Even after replacing the D2S xenon bulbs, they were so dim at night I could no longer drive the vehicle. I either needed new headlight housings, or I could refurbish my originals.

I decided to take apart the headlights, by removing 3 screws holding the lens to the housing, and using a heat gun around the perimeter of the housing to melt the butyl sealant to pull the lens off; this was the most challenging part. Be careful not to crack the inside chrome housing.

I then removed the projector by removing more screws which allowed me to see how badly the projector bowls were burnt. I covered the bowls with HVAC foil tape, made sure everything was clean and put it all back together. I used the heat gun to melt the sealant to allow me to push lens back onto the housing, and used a C-Clamp to further clamp things together.

I wet sanded and buffed my headlamps and fog lamps. I also installed LEDs in my fog lamps. I

After refurbishing the headlamps, the output is significantly better. The alternative to this is to simply buy new headlamp housings. A lot of other vehicles of this era using projectors with HID xenon systems suffer the same fate with degraded output due to burnt projector bowls.

I owned this 2009 Acura from brand new, so I decided to invest some time here to keep the vehicle going for a while longer.

Front end off to get the headlights off:
https://cimg1.ibsrv.net/gimg/acurazi...2888ba7936.png

Lens OFf:
https://cimg7.ibsrv.net/gimg/acurazi...ec764f84aa.png

Burnt Projector Bowl (passenger side):
https://cimg8.ibsrv.net/gimg/acurazi...7f0a599711.png

Degraded projector bowl (driver side):
https://cimg0.ibsrv.net/gimg/acurazi...17e1e7d346.png

Foil tape applied to burnt areas of projector bowl:
https://cimg2.ibsrv.net/gimg/acurazi...14c0710f3c.png

Wet sanded and buffed:
https://cimg9.ibsrv.net/gimg/acurazi...3dcb44385b.png

Night output is near new again:
https://cimg8.ibsrv.net/gimg/acurazi...1c52ebaaa3.png

+1 for thinking out of the box, but I'm hesitant that the HVAC tape solution will last very long. Since you were already going through the trouble of taking the entire headlamp apart, sourcing another better condition projector/bowl would have been trivial at that point.


Keep us posted on the long term review but I suspect the HVAC tape (or its associated adhesive) will fail over time, Kudos for thinking outside the box nevertheless!

Yeah you are probably right on the HVAC tape, it is what I read others used however to do the repair on other vehicles. It is rated for high temperatures.