GMT400Tahoe
OBS Enthusiast
THIS THREAD A WORK IN PROGRESS, NOT YET COMPLETE
This is a build thread to document the projector retrofits I have built for my GMT400 platform Chevrolet Tahoe. There is information regarding two different retrofits in this thread:
The budget build installed on my 2000 Chevrolet Tahoe Z71. Yellowstone National Park.
The budget build installed. Xenon low beam illuminated. DRL still activated but receiving full power from relay harness instead of reduced power from vehicle wiring.
The budget build installed. Illumination of both bi-xenon high beam and halogen high beam via 4 high mod.
Close-up view of the budget build installed. Notice defluted area in lens directly in front of projector.
Purpose:
This is a build thread to document the projector retrofits I have built for my GMT400 platform Chevrolet Tahoe. There is information regarding two different retrofits in this thread:
- Budget build that I did as a proof-of-concept. This allowed me to see if I could do it without wasting too much money if I could not complete the project. This was moderately difficult but manageable.
- A high-end build that I did with the best components. Once I knew I could do a retrofit on these vehicles, I wanted to build another one with the best parts. This build was more difficult because the high-end projectors are generally larger and even more difficult to fit in the shallow GMT400 headlight housings.
You must be registered for see images attach
The budget build installed on my 2000 Chevrolet Tahoe Z71. Yellowstone National Park.
You must be registered for see images attach
The budget build installed. Xenon low beam illuminated. DRL still activated but receiving full power from relay harness instead of reduced power from vehicle wiring.
You must be registered for see images attach
The budget build installed. Illumination of both bi-xenon high beam and halogen high beam via 4 high mod.
You must be registered for see images attach
Close-up view of the budget build installed. Notice defluted area in lens directly in front of projector.
Purpose:
Without going into too much detail, a projector retrofit is really the only way to correctly do high intensity discharge (HID) lighting.
Plug-and-play (PnP) HID where bulbs are thrown in reflectors or projectors made for halogen lighting result in scattered light that does not provide an improvement in functional light output and scatters light in directions that blind oncoming drivers. This is because the source of light in a halogen bulb is at a different location from the source of light in a HID bulb is different still from the source of light in a light emitting diode (LED) bulb. The net result is that PnP HID or PnP LED provides a decrease in functional light output relative to simply a good set of halogen bulbs in reflector housings. People think their PnP HID lights are providing better light output, but in reality the hot spot of light that illuminates down the road is actually decreased and everyone else on the road thinks they are a turd with the blue light they scatter in all directions (unfortunately back before I learned about projector retrofitting I used to be one of those annoying drivers when I had a PnP kit on my old Tahoe).
In contrast, installing a projector that is specifically designed for HID can provide the desired increased light output that is properly controlled and focused on the road, all while preventing the blinding of oncoming drivers that is associated with PnP.
An additional benefit of projector retrofitting is that many projectors are bi-xenon, indicating that the shield within the projector that generates the desired sharp cutoff can be moved out of the way when the high beams are activated, allowing the same bulb and projector that function primarily as a low beam to instantly provide high beam illumination. In order for the bi-xenon function to work on our GMT400 platform vehicles the 4-high headlight modification must have already been completed. The 4 hi mod is an easy modification that allows the low beams to remain illuminated when the high beam is selected, good information on that found in the following 1,2,3 posts.
In contrast, installing a projector that is specifically designed for HID can provide the desired increased light output that is properly controlled and focused on the road, all while preventing the blinding of oncoming drivers that is associated with PnP.
An additional benefit of projector retrofitting is that many projectors are bi-xenon, indicating that the shield within the projector that generates the desired sharp cutoff can be moved out of the way when the high beams are activated, allowing the same bulb and projector that function primarily as a low beam to instantly provide high beam illumination. In order for the bi-xenon function to work on our GMT400 platform vehicles the 4-high headlight modification must have already been completed. The 4 hi mod is an easy modification that allows the low beams to remain illuminated when the high beam is selected, good information on that found in the following 1,2,3 posts.
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