How to: OEM HID headlights with NO ECU Coding!!!
02-27-2017, 12:40 PM
#1
Newbie
Thread Starter
How to: OEM HID headlights with NO ECU Coding!!!
Disclaimer: I am not responsible for you or your vehicle. The below how to is my experience, yours may be different depending on the parts, skills, and vehicle involved.
Like most of you, my 04 C230 has halogens from the factory. I did a bunch of research and saw that the ECU has to be coded "xenon present" to make the HID lights work. I checked with several shops and my dealer in my area and no one was able or willing to recode the ECU for me. Despite this, I scored a killer deal on a pair of OEM HID lights out of an 04 sedan that was flooded. I got the whole car car cheap, which turned out to be key to making this work.
the OEM halogen lights use a single 5 wire plug on each housing. Those wires are grey/red, brown, yellow, white, and grey/black.
the OEM HID headlights have 3 plugs on the passengers wide light, and two on the driver's side. These extra plugs are for the self leveling system in the HID light cars. The good news is that all of the headlight functionality, besides the self leveling, is done through the exact same plug, with the exact same wire pinning, as the halogen headlights. it makes them bolt in, and plug in.
the issue that arises however, is that the ECU is monitoring power consumption of the circuit, and since the HID lights use 35 watts of power, and the halogen lights use 55, plugging in HID lights into a halogen car causes the ECU to think there is a malfunction in the headlight circuit and shut the light off. The correct way around the issue is to have the ECU recoded for HID lights, but as I found out, it is hard to do since few Indy shops have the capability, and the dealer is unwilling.
The good news is that if you have access to a spare or broken set of halogen headlights buckets (or are willing to cut yours up), and have a donor car you can cut a few feet of harness out of, it is easy to make a jumper harness that will allow the HID headlights to run in a halogen car.
Step 1:
You will need the following.
Tools:
-Basic set of metric hand tools
-Jack
-Jack stands
-Soldering iron
-Wire cutters/strippers
-Drill
-Drill bits
-an 8-32 tap
-vise
-hacksaw
-torque wrench
Materials:
-A pair of OEM HID headlights
-Approximately 4' of OEM wiring harness from the male headlight plug on each side. Halogen cars would be a better donor since the harness wiring appears to be a larger gage, but wiring from an HID car will work too. Try to strip back the harness with the brown ground wires all the way to where the ring terminal bolts to the body ground stud. This is the worst part of the job, getting the donor harness out of the donor vehicle.
-electrical solder
-various sizes of heat shrink tube
-soldering flux
-liquid electrical tape (for waterproofing)
-friction tape (NOT electrical tape!) for harness wrapping.
-thermal transfer paste (like what's used to transfer heat from computer CPUs to the heat sinks)
-(8) 8-32 x 1" screws
-(4) 6x1.0mm bolts (I used the torx bolts that hold the door stop to the unibody out of my parts car. They look OEM on the car)
-(8) 1/8" thick fender washers. I think mine were 3/8" hole if I remember right.
-(8) 6mm washers
-(2) 6mm nuts
-(1) piece of 2" wide by 36" long by 3/16 or 1/4" thick aluminum. We will make the heat sinks out of this.
-(2) 4700 uF 35V capacitors
-(2) 10 ohm, 20 watt 5% ceramic resistors.
-roll of duct tape
I recommend ordering extra resistors and capacitors. They're cheap in the grand scheme of things. I'd order at least one extra pair that way if something goes wrong, it's an easy fix.
Once all your materials and tools are gathered, you're ready to start. I recommend you do this on the weekend and have a method of getting around in case something goes sideways and you need to run to the store.
Step 2:
Before proceeding further: I recommend using the pigtail from the donor car to verify the headlights are fully functioning. Plug the harness into the HID headlight, then attach the brown wire to a battery negative or ground, or the negative on a 14v power supply, then one by one, connect each of the other wires to the positive side of the battery/power supply. Different circuits will power up with each wire. The grey wires will power the turn signal and running lights, the yellow the HID, and the white the high beam. To check the high beam functionality, connect both the yellow and white wires to the positive of the battery at the same time. This will strike the HID, as well as raise the shield on the bixenon and power the halogen high beam bulb. You will hear the shield moving inside the headlight when you connect the white wire. Next, once the light functionality has been verified, cut the female connector out of the halogen housings using the hacksaw. Be careful not to damage the connector or the wires inside. Break the headlight down as much as possible to get as much wire length attached to the connector inside the headlight as possible.
Step 3:
Decide how long you want your jumper harnesses to be. Mine are about 14" from connector to connector but it would be nice if they were longer. I recommend 24". WITH THE EXCEPTION OF THE YELLOW AND BROWN WIRES: Cut your wires on the pigtails on the connectors from the headlights, and from the donor harness to that total length. Leave the yellow and brown as long as possible. I recommend staggering your junctions so you don't have all 5 wires being spliced at the same spot.
Step 4:
Strip and solder white to white, grey/red to grey/red, and grey/black to grey/black. On the yellow and brown wires, you will cut away part of the insulation where the junction will be, but not cut the wire. Once the insulation is stripped from the yellow and brown wires where the junctions will be, solder yellow to yellow and brown to brown. Heat shrink and/or liquid electrical tape the connections as you go! When you're done with this step you should now have two 24" long jumper harnesses that have a grey female plug on one end, and a black male plug on the other. The grey female plug is going to plug into your OEM car harness, and the black connector will plug into the HID headlight. Hanging off these two harnesses, you'll have a yellow lead, and a brown lead. On to the next step.
Step 5:
On the yellow and brown leads off each harness, solder in the capacitors. Do not cut the leads down, strip the insulation back and solder them in. Capacitors have a polarity, typically speaking, the longer pin on the capacitor is the negative, and should be soldered to the brown wire. The positive pin is shorter and will go to the yellow wire. Make sure you get it right, if you don't, the capacitor will explode!
Step 6:
At the end of the yellow lead, solder in the 10 ohm resistor, one on each harness. Strip the insulation on the brown wires and solder to the other side of the resistor. Resistors are not polarity sensitive, it can go in either way. At the end of this step, you should now have a 4 legged harness. One leg is the ring terminal on the brown ground lead, one leg is the soldered in capacitor/resistors, one leg will be the grey plug, and the last leg the black plug.
Step 7:
If you haven't done so, finish waterproofing the capacitor with the liquid electrical tape. Slather both ends with it and let it dry. Capacitors do not heat up, so there will be no danger of overheating it.
Step 8:
Wrap the legs of the harness in friction tape. Friction tape can be found in the electrical section of home improvement stores, and feels like sticky cloth electrical tape. It's the stuff the OEM harness was wrapped in. The capacitor can be wrapped tightly to the harness, but the resistor should be left open and free, it will get very hot, somewhere on the order of 170 degrees Fahrenheit, when the harness is running.
Step 9:
Set the harnesses aside, and cut two sections of aluminum approximately 8-9" long. I bolted these to the body where the core support meets the fender structure. The resistors will be clamped to these pieces of aluminum, and will get very warm/hot in operation.
Step 10:
Drill 2 holes in one end of each piece of aluminum for 6mm bolts to bolt it to the body. Use the body holes where the front fender meets the core support for a template.
Step 11:
Drill 4 5/32" holes in a rectangular patten on the opposite end of the aluminum bars. The 8 8-32 screws (4 per plate) will pass through these holes, around the resistor, and thread into a second aluminum plate we will make in the next step.
Step 12:
Using the hacksaw and vise, cut 2 pieces of aluminum off the original piece. They should be approximately 2 1/2" long.
Step 13:
Using the two brackets as a template, mark the location of the (4) 5/32" holes into the two shorter pieces of aluminum. Clamp those pieces in the vise and drill 4 #29 drill bit holes in each piece.
Step 14:
Using the 8-32 tap, thread the holes drilled in step 13.
Step 15:
Carefully apply a thin layer of thermal paste to the top and bottom of the resistor on each harness, stick the resistor between the sets of holes on each aluminum heat sink plate, then stick the shorter piece of aluminum plate with the threaded holes to the underside of each resistor. Pass an 8-32 screw through the 4 holes and tighten until the thermal past squeezes out from under the resistor. DO NOT OVERTIGHTEN!! If you overtighten the screws, you WILL crack and fail the resistor. The screws have to be just a shade tighter than finger tight!!
Step 16:
Park the car facing a flat smooth surface, like a garage door. Using duct tape, mark the centerline of the front wheels on the driveway. Turn the halogen headlights on, and mark the edge of the beam cutoff on the door or wall with the duct tape as well. This is for aligning the HID lights later.
Step 17:
Remove the front bumper and headlights from the car. There are plenty of how tos on YouTube for this step.
Step 18:
Bolt the aluminum heat sinks to the end of the core support/fender support using the 6mm hardware. Use the 3/8" thick fender washers, double stacked, as a spacer over each hole to prevent the aluminum sink from bending the edge of the core support and fender where it is rolled upwards.
Step 19:
Plug the harness into the OEM harness, and bolt the ring terminal on the brown wire to the body stud up by the shock tower.
Step. 20
Install the headlights into the car. Plug in your jumper harness. Start the car, and check functionality. I recommend letting it idle with the lights on for 15-20 minutes to make sure there are no issues.
WARNING: the resistors will get VERY hot. Around 170 degrees hot. They need to be booted to the heat sinks, and not touching anything but the metal mount when you first strike the HIDs in the car! You have been warned!
Step 21:
Once the burn in/functions test is complete, zip tie the jumper harness down to prevent movement. Try not to pull or strain the wires, but don't let them move either. This is very important at the resistor and at the plugs for long term wire life due to vibration/solder joint fatigue.
Step 22:
Reassemble the front bumper, and celebrate a job well done!!!
Other notes:
My headlights were a bit hazy. I wet sanded the lenses with 1000, 1500, 2000, 3,000, and 5,000 grit, and then polished them with meguiars plastix compound. They now look brand new!
I cannot stress enough how important it is that the resistors not touch anything but their heat sinks. They will get very hot. Above 140 degrees can cause second degree burns in less than a second. In addition to a danger to you, they could cause a fire on the car if they touch anything but the heat sinks!!
Any questions, feel free to ask. I will try to get some pictures up shortly.
Like most of you, my 04 C230 has halogens from the factory. I did a bunch of research and saw that the ECU has to be coded "xenon present" to make the HID lights work. I checked with several shops and my dealer in my area and no one was able or willing to recode the ECU for me. Despite this, I scored a killer deal on a pair of OEM HID lights out of an 04 sedan that was flooded. I got the whole car car cheap, which turned out to be key to making this work.
the OEM halogen lights use a single 5 wire plug on each housing. Those wires are grey/red, brown, yellow, white, and grey/black.
the OEM HID headlights have 3 plugs on the passengers wide light, and two on the driver's side. These extra plugs are for the self leveling system in the HID light cars. The good news is that all of the headlight functionality, besides the self leveling, is done through the exact same plug, with the exact same wire pinning, as the halogen headlights. it makes them bolt in, and plug in.
the issue that arises however, is that the ECU is monitoring power consumption of the circuit, and since the HID lights use 35 watts of power, and the halogen lights use 55, plugging in HID lights into a halogen car causes the ECU to think there is a malfunction in the headlight circuit and shut the light off. The correct way around the issue is to have the ECU recoded for HID lights, but as I found out, it is hard to do since few Indy shops have the capability, and the dealer is unwilling.
The good news is that if you have access to a spare or broken set of halogen headlights buckets (or are willing to cut yours up), and have a donor car you can cut a few feet of harness out of, it is easy to make a jumper harness that will allow the HID headlights to run in a halogen car.
Step 1:
You will need the following.
Tools:
-Basic set of metric hand tools
-Jack
-Jack stands
-Soldering iron
-Wire cutters/strippers
-Drill
-Drill bits
-an 8-32 tap
-vise
-hacksaw
-torque wrench
Materials:
-A pair of OEM HID headlights
-Approximately 4' of OEM wiring harness from the male headlight plug on each side. Halogen cars would be a better donor since the harness wiring appears to be a larger gage, but wiring from an HID car will work too. Try to strip back the harness with the brown ground wires all the way to where the ring terminal bolts to the body ground stud. This is the worst part of the job, getting the donor harness out of the donor vehicle.
-electrical solder
-various sizes of heat shrink tube
-soldering flux
-liquid electrical tape (for waterproofing)
-friction tape (NOT electrical tape!) for harness wrapping.
-thermal transfer paste (like what's used to transfer heat from computer CPUs to the heat sinks)
-(8) 8-32 x 1" screws
-(4) 6x1.0mm bolts (I used the torx bolts that hold the door stop to the unibody out of my parts car. They look OEM on the car)
-(8) 1/8" thick fender washers. I think mine were 3/8" hole if I remember right.
-(8) 6mm washers
-(2) 6mm nuts
-(1) piece of 2" wide by 36" long by 3/16 or 1/4" thick aluminum. We will make the heat sinks out of this.
-(2) 4700 uF 35V capacitors
-(2) 10 ohm, 20 watt 5% ceramic resistors.
-roll of duct tape
I recommend ordering extra resistors and capacitors. They're cheap in the grand scheme of things. I'd order at least one extra pair that way if something goes wrong, it's an easy fix.
Once all your materials and tools are gathered, you're ready to start. I recommend you do this on the weekend and have a method of getting around in case something goes sideways and you need to run to the store.
Step 2:
Before proceeding further: I recommend using the pigtail from the donor car to verify the headlights are fully functioning. Plug the harness into the HID headlight, then attach the brown wire to a battery negative or ground, or the negative on a 14v power supply, then one by one, connect each of the other wires to the positive side of the battery/power supply. Different circuits will power up with each wire. The grey wires will power the turn signal and running lights, the yellow the HID, and the white the high beam. To check the high beam functionality, connect both the yellow and white wires to the positive of the battery at the same time. This will strike the HID, as well as raise the shield on the bixenon and power the halogen high beam bulb. You will hear the shield moving inside the headlight when you connect the white wire. Next, once the light functionality has been verified, cut the female connector out of the halogen housings using the hacksaw. Be careful not to damage the connector or the wires inside. Break the headlight down as much as possible to get as much wire length attached to the connector inside the headlight as possible.
Step 3:
Decide how long you want your jumper harnesses to be. Mine are about 14" from connector to connector but it would be nice if they were longer. I recommend 24". WITH THE EXCEPTION OF THE YELLOW AND BROWN WIRES: Cut your wires on the pigtails on the connectors from the headlights, and from the donor harness to that total length. Leave the yellow and brown as long as possible. I recommend staggering your junctions so you don't have all 5 wires being spliced at the same spot.
Step 4:
Strip and solder white to white, grey/red to grey/red, and grey/black to grey/black. On the yellow and brown wires, you will cut away part of the insulation where the junction will be, but not cut the wire. Once the insulation is stripped from the yellow and brown wires where the junctions will be, solder yellow to yellow and brown to brown. Heat shrink and/or liquid electrical tape the connections as you go! When you're done with this step you should now have two 24" long jumper harnesses that have a grey female plug on one end, and a black male plug on the other. The grey female plug is going to plug into your OEM car harness, and the black connector will plug into the HID headlight. Hanging off these two harnesses, you'll have a yellow lead, and a brown lead. On to the next step.
Step 5:
On the yellow and brown leads off each harness, solder in the capacitors. Do not cut the leads down, strip the insulation back and solder them in. Capacitors have a polarity, typically speaking, the longer pin on the capacitor is the negative, and should be soldered to the brown wire. The positive pin is shorter and will go to the yellow wire. Make sure you get it right, if you don't, the capacitor will explode!
Step 6:
At the end of the yellow lead, solder in the 10 ohm resistor, one on each harness. Strip the insulation on the brown wires and solder to the other side of the resistor. Resistors are not polarity sensitive, it can go in either way. At the end of this step, you should now have a 4 legged harness. One leg is the ring terminal on the brown ground lead, one leg is the soldered in capacitor/resistors, one leg will be the grey plug, and the last leg the black plug.
Step 7:
If you haven't done so, finish waterproofing the capacitor with the liquid electrical tape. Slather both ends with it and let it dry. Capacitors do not heat up, so there will be no danger of overheating it.
Step 8:
Wrap the legs of the harness in friction tape. Friction tape can be found in the electrical section of home improvement stores, and feels like sticky cloth electrical tape. It's the stuff the OEM harness was wrapped in. The capacitor can be wrapped tightly to the harness, but the resistor should be left open and free, it will get very hot, somewhere on the order of 170 degrees Fahrenheit, when the harness is running.
Step 9:
Set the harnesses aside, and cut two sections of aluminum approximately 8-9" long. I bolted these to the body where the core support meets the fender structure. The resistors will be clamped to these pieces of aluminum, and will get very warm/hot in operation.
Step 10:
Drill 2 holes in one end of each piece of aluminum for 6mm bolts to bolt it to the body. Use the body holes where the front fender meets the core support for a template.
Step 11:
Drill 4 5/32" holes in a rectangular patten on the opposite end of the aluminum bars. The 8 8-32 screws (4 per plate) will pass through these holes, around the resistor, and thread into a second aluminum plate we will make in the next step.
Step 12:
Using the hacksaw and vise, cut 2 pieces of aluminum off the original piece. They should be approximately 2 1/2" long.
Step 13:
Using the two brackets as a template, mark the location of the (4) 5/32" holes into the two shorter pieces of aluminum. Clamp those pieces in the vise and drill 4 #29 drill bit holes in each piece.
Step 14:
Using the 8-32 tap, thread the holes drilled in step 13.
Step 15:
Carefully apply a thin layer of thermal paste to the top and bottom of the resistor on each harness, stick the resistor between the sets of holes on each aluminum heat sink plate, then stick the shorter piece of aluminum plate with the threaded holes to the underside of each resistor. Pass an 8-32 screw through the 4 holes and tighten until the thermal past squeezes out from under the resistor. DO NOT OVERTIGHTEN!! If you overtighten the screws, you WILL crack and fail the resistor. The screws have to be just a shade tighter than finger tight!!
Step 16:
Park the car facing a flat smooth surface, like a garage door. Using duct tape, mark the centerline of the front wheels on the driveway. Turn the halogen headlights on, and mark the edge of the beam cutoff on the door or wall with the duct tape as well. This is for aligning the HID lights later.
Step 17:
Remove the front bumper and headlights from the car. There are plenty of how tos on YouTube for this step.
Step 18:
Bolt the aluminum heat sinks to the end of the core support/fender support using the 6mm hardware. Use the 3/8" thick fender washers, double stacked, as a spacer over each hole to prevent the aluminum sink from bending the edge of the core support and fender where it is rolled upwards.
Step 19:
Plug the harness into the OEM harness, and bolt the ring terminal on the brown wire to the body stud up by the shock tower.
Step. 20
Install the headlights into the car. Plug in your jumper harness. Start the car, and check functionality. I recommend letting it idle with the lights on for 15-20 minutes to make sure there are no issues.
WARNING: the resistors will get VERY hot. Around 170 degrees hot. They need to be booted to the heat sinks, and not touching anything but the metal mount when you first strike the HIDs in the car! You have been warned!
Step 21:
Once the burn in/functions test is complete, zip tie the jumper harness down to prevent movement. Try not to pull or strain the wires, but don't let them move either. This is very important at the resistor and at the plugs for long term wire life due to vibration/solder joint fatigue.
Step 22:
Reassemble the front bumper, and celebrate a job well done!!!
Other notes:
My headlights were a bit hazy. I wet sanded the lenses with 1000, 1500, 2000, 3,000, and 5,000 grit, and then polished them with meguiars plastix compound. They now look brand new!
I cannot stress enough how important it is that the resistors not touch anything but their heat sinks. They will get very hot. Above 140 degrees can cause second degree burns in less than a second. In addition to a danger to you, they could cause a fire on the car if they touch anything but the heat sinks!!
Any questions, feel free to ask. I will try to get some pictures up shortly.
Last edited by ETN; 02-27-2017 at 12:56 PM.
02-27-2017, 01:05 PM
#2
Newbie
Thread Starter
A few other things I forgot to mention:
the capacitor supplies stored energy during headlight startup. If the voltage dips, the ECU will think there is an issue and cut power to the circuit. The capacitor is there to prevent this.
the resistor consumes the extra 20 watts of power the HID headlight does not, thereby "tricking" the ECU into thinking it is a halogen load on the circuit.
once the headlights are in, and it starts to get dark, level the headlights using your duct tape marks and the black threaded insert screws under the headlight mounting bolts. There are also black screws facing upwards on the grey plastic housing of the headlight. These manually turn the self leveling components up and down inside the housing. If you go too far with them, you'll actually thread the projector off the screw, and you'll see the HID light shaking inside the housing with car vibration. To fix this, shut the headlights and the car off, pop the black plastic cover on the back of the headlight, and pull upward gently on the HID assembly while turning the adjustment screw clockwise. This will thread the projector back onto the leveling mechanism DO NOT do this with the headlights or engine on. The accessory belt could severely injure you, and HID lights run at 25,000 volts. If the connector were to come loose while you were holding it you would be severely electrocuted!!! Again, you have been warned!!
the capacitor supplies stored energy during headlight startup. If the voltage dips, the ECU will think there is an issue and cut power to the circuit. The capacitor is there to prevent this.
the resistor consumes the extra 20 watts of power the HID headlight does not, thereby "tricking" the ECU into thinking it is a halogen load on the circuit.
once the headlights are in, and it starts to get dark, level the headlights using your duct tape marks and the black threaded insert screws under the headlight mounting bolts. There are also black screws facing upwards on the grey plastic housing of the headlight. These manually turn the self leveling components up and down inside the housing. If you go too far with them, you'll actually thread the projector off the screw, and you'll see the HID light shaking inside the housing with car vibration. To fix this, shut the headlights and the car off, pop the black plastic cover on the back of the headlight, and pull upward gently on the HID assembly while turning the adjustment screw clockwise. This will thread the projector back onto the leveling mechanism DO NOT do this with the headlights or engine on. The accessory belt could severely injure you, and HID lights run at 25,000 volts. If the connector were to come loose while you were holding it you would be severely electrocuted!!! Again, you have been warned!!
