I completed my projector retrofit a few weeks ago. I have been fine tuning the aim since then, and nearly have it where I want it. I figured I would make a thread logging my experience, and include helpful tips and pointers for people to reference in the future. This won't be a step-by-step tutorial, but there are a lot of guides on the internet if you are interested in doing a retrofit yourself.
First, a little background information. It's no secret that the stock headlights on 99-04 Mustangs are pretty terrible at illuminating the road. Even after installing Philips X-treme Vision bulbs–pretty much the brightest halogen bulbs available–I was still unsatisfied with the output at night. For years, New Edge owners have had little option for improving the performance of their lighting system. Recently, however, aftermarket plug-and-play HID and LED kits have emerged as such technology becomes standard on modern cars. These kits are appealing due to their low cost, ease of installation, and increased light output. For many, this is an adequate "upgrade" to stock Halogen bulbs. But don't be fooled. Installing a plug-and-play HID kit in a reflector housing not only produces blinding glare for oncoming traffic, but actually diminishes your ability to see long distances at night. That's right. These HID kits with their increased Lux and pure white light actually perform worse than the Halogen bulbs they replace. Here's a good read on HID kits and why they don't work well in a reflector housing:
Daniel Stern Lighting Consultancy and Supply
Now, on to the good stuff. Here's the breakdown of parts I used:
OEM Ford headlights
Morimoto Mini D2S 4.0 projectors
Osram CBI bulbs
Morimoto relay harness
Matsushita Gen IV ballasts
I chose the MD2S over the Mini H1 projector because they have a larger and more intense hotspot, put out more width, have an incredibly bright high beam, and can use OEM grade D2S bulbs. In terms of physical dimensions, the MD2S is longer and taller than the MH1. Since the headlights for these cars are rather slim, there's not much room to work with (I'll talk more on that later). A MH1 would have been easier to install, but I wanted the increased performance of the MD2S. Here's what the projectors look like:
The first step to any retrofit is opening the stock headlight housings. Most aftermarket lights are sealed with Butyl, which softens and almost liquefies with heat. Lights sealed with Butyl are a cinch to open. In stark contrast, OEM Ford lights are sealed with permaseal. This stuff more closely resembles plastic when cured, and only becomes slightly pliable when heated. I read countless horror stories about opening permasealed lights, but in my experience, they aren't all that bad to work on. Heating the lights in an oven at 240˚F for 20-minutes softens the permaseal enough to work with. Remember to wear oven mitts or appropriate gloves when handling hot lights. Whether you use OEM or aftermarket lights, here's the best advice I can give you when cracking them open: get yourself a pair of expanding pliers. These are the pair I bought:
These pliers were absolutely invaluable for opening the lights. I found the best spot to start with is the outside edge (see photo below). There is less sealant there, and there's a nice lip for the pliers to pry against. After the front lens began to separate from the back housing, I used a flathead screwdriver and worked it along the channel to help sever the seal. I continued using the screwdriver and pliers along the outside of the headlight until the lens was fully separated. The first light took a couple hours to open, but I had the second one apart in less than 30-minutes. Several more rounds of heating were then needed to remove all the permaseal from the channels.
Once everything was opened up, I began the actual retrofit process. Most of the modifications are done to the reflector bowl, since that is what the projector is mounted to. There are several methods when mounting projectors, and each depends on what projector is used, and what car they are going on. OEM projectors are usually mounted using bolts, while some aftermarket projectors–like the Morimoto MD2S and MH1–use a threaded shaft that inserts through the stock bulb opening. Generally speaking, the threaded shaft method is far easier. For a more detailed look at the various mounting methods, check out this video:
The next steps were fairly straight forward, so I'll try and keep this brief. The stock headlights use a 9007 Halogen bulb. The back of the reflector is designed to mount this style bulb, which means some cutting and sanding is necessary in order for the threaded shaft of the projector to fit. A Dremel with a cutoff wheel was perfect for cutting down the base of the bulb holder. Then I used an orbital sander with a 80-grit disc to sand down the base until it was smooth. It's important to ensure the base is sanded perfectly level, as the threaded shaft will eventually be secured with a lock ring. If the base is sanded at an angle the projector will sit crooked, and light won't shine where you want it–straight ahead! The threaded shaft has an outside diameter of 35mm, and it becomes obvious that the stock bulb opening is far too small and needs to be enlarged. I slowly opened up the hole with a Dremel and sanding drums until the threaded shaft could fit without rubbing. After cutting and sanding, this is what I got:
The following would probably not have been needed had I used a MH1 projector because of its smaller size. The MD2S 4.0 has two "legs" that extend downward from the rest of the projector. These legs hit the bottom of the reflector bowl, causing the projector to sit upward at an angle. In order for the projector to sit properly, the bottom of the reflector had to be cut. You can see the hole I cut in the photo below. Another reason to cut the reflector is to allow the projector to rotate freely. Because HID projectors have such a sharp cutoff, they are very sensitive to improper rotation. The last thing you want after sealing the lights back up is to see the cutoff angled to one side. Since I cut the reflector bowl, I can freely rotate the projector to make sure the cutoff is always level.
Once the projectors were mounted in the reflectors, I needed to trim and mount the shrouds. There are over two-dozen different shrouds to choose from, coming in different designs and sizes. I personally prefer either the E46-R or Iris style shroud since they have the cleanest look. For this retrofit, I opted for the E46-R shrouds, but nearly every shroud requires some degree of trimming to fit in 99-04 Mustang headlights. In my case, the top part of the shrouds required a good amount of trimming and sanding to fit. Since the reflector moves up and down when the lights are adjusted vertically, I had to make sure the shrouds did not rub or bind on the black inner bezel.
I want to add a quick word on mounting the shrouds. The most common methods are either using centric rings (can only be used on projectors with 2.5" lens), or using some sort high-heat adhesive such as JB Weld. Neither method seemed particularly reliable to me, so I improvised my own technique. I drilled holes through the bottom of the reflector bowls and shrouds, fed bolts through the holes, and secured them with nylon lock nuts. This ensures a far more durable mount for the shroud. You can see the bottom of the bolts in the following photo:
After ensuring everything fit and looked correctly, I sealed the lights back up using Morimoto Retrorubber. This is a Butyl sealant, which means the lights will be easier to re-open in the future if any alterations or repairs are needed.
Here's the final result:
Crappy cellphone photos of the cutoff at night. The light appears slightly yellow, but in reality it's pure white. These projectors have a 3" clear lens that produce a really sharp and colorful cutoff.
High beam shot from the driver seat. INSANELY BRIGHT!
After driving with the new lights for a few weeks, I am thrilled with their performance. There really is no comparison between the stock Halogen lights and these. Long distance visibility is greatly improved, and the DOT cutoff means I won't blind oncoming traffic.
If you have any questions, feel free to ask.