ml320 HID headlight, one not working
02-11-2015, 02:26 PM
#26
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2002 ml320
Do your extra high beams halogens work?
Jimbo, I take it your vehicle spec is U.S so does your halogen high beams come on when the lever is switched to the high beam mode? Not that I need them as the HID has a motor that directs the light to a high beam mode when the lever is moved to that position. Just wondering what's stopping the others from coming on.
01-08-2019, 02:41 PM
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2002 ML320, 2006 CLK350, 2015 ML350, 2012 CTS4, 69 Z28, 87 C4
ML320 2002 Xenon Headlights:
They are nice looking cars and the xenon headlights are extra special bright, and so I figure they are worth the trouble.
They are available in different wavelengths, and my current favorite is 10k bulbs that are thought to be the brightest. I am still running a 6k bulb on the other side. Mine have gone out a few times. The bulbs are 2 for $10 on EBay.
Based on VIN number, Autohaus in Northbrook, IL says that my 2002 ML320 was sold with the following Xenon parts, although the parts are usually sold for the 2003-2008 models. Some Mercedes dealers will give you the parts numbers and others have wised up and won't because they have found that giving you the parts numbers makes it too easy for you to search for parts cheap Chinese knock off and/or bootleg parts at lower cost on EBay.com.
Description, OEM Price, OEM Part No., Remark, EBay price
igniter/transformer, $182 OEM, 0028202526, plugs into bulb, $36 EBay, is thought to contain a 12 Vac to 77 Vac step up transformer for Xenox bulbs
control unit/ballast, $545 OEM, 0028202326, capacitor and relays, $26 EBay, it's thought to contain a capacitor to fire arc, relays, control logic, DC to AC
bulb, $140 OEM, 910139000001, bulb, 2 for $10 EBay, search for part numbers the dealer gives you for your build or try the part numbers provided above
Mercedes typically charges $170 for the diagnosis. You can replace the three parts yourself in 10 minutes.
EBay also has a $64 kit containing all three components that presumably match. It is hardly ever the wiring or the headlight switch. There appear to be two different bulb types that look the same but are not electrically interchangeable. The first two times it was bulbs (EBay 2 for $15 at the time). The third time it was an igniter/transformer (EBay $41 at the time now $36). The 4th time was resolved this weekend when the $26 control unit/Ballast was replaced. And so I've had headlight outages at one time or another from the three most common failures (bulb, igniter, ballast) in a 130k mi 2002 ML320. The 4th time, both the high and low beam was blinking on the right side. I replaced the bulb and igniter/transformer and that didn't stop the blinking. Replacing the ballast stopped the blinking the 4th time the headlights experienced a failure.
So far, it has been a lot like working on florescent lights in your house which have the same 3 parts on the old style units. A pattern has developed. It is easy to work on these headlights. You remove the entire headlight assembly with 1 screw top side and two nuts along the bottom. There is a hinged swinging plastic part under the headlight that conceals the bottom two headlight bolts. One side of the hinged swinging plastic part under the headlight is clipped to the grill. You unfasten the clip, swing the plastic cover to the side and unfasten the three headlight assembly screws. That swinging cover is a fairly delicate piece and you can remove it entirely by pushing towards the vehicle on the center of the hinge to remove the center plastic hinge piece and then pushing in slightly on the outer hinged side in a circular motion in and then towards the center of the grill with zero force, you are merely guiding it off. Otherwise, you break the hinged part or chip the paint off the corner of the fender. And the paint does chip and the fender does start rusting there if you try to bully it off. Once you have the headlight assembly off, a simple plastic cover on the rear of the headlight assembly is unsnapped to expose the igniter. On the right side, the igniter and bulb can be replaced without removing the overall headlight assembly, but it would probably take some experience with all the plastic parts to get them off without breaking them. You'll be happier removing the entire headlight assembly. On the driver side, forget about going half way because there is not enough room to pull the igniter cover off the headlight assembly without removing the headlight assembly. When reinstalling the headlight assembly, sit on the ground and focus 90% of your attention on making a centered alignment of the two bottom posts in the headlight assembly. If you do it the other way and focus on the top of the headlight assembly, the top snap goes in and one of the bottom posts might have missed the holes and the top plastic tab on the top of the headlight assembly is nearly impossible to release again without breaking off the plastic tab. It is hard to say if their engineers are just plain stupid, or they designed it that way to sell more headlight assemblies. I'm pretty sure that the headlight will stay on just fine with that top plastic snap broken off as long as you still have the top screw hole intact.
The igniter/transformer is removed by pushing in a little and twisting 1/16 of a turn in the indicated direction. Don't force it because the little plastic prongs break off and render the igniter useless. If you try to use an igniter with a prong missing, the high resistance connection melts the igniter to the bulb and you lose them both as a best case scenario, and start a fire worse case scenario. There is a sticker on the igniter that indicates direction to twist on/off. There are a couple of metal wire clips that are unsnapped to remove the bulb. Use gloves and don't touch the bulb and leave hand oil on it or it won't work for long. The ballast is a relatively flat 3" x 4" x 3/4" cast metal box that is attached to the bottom of the headlight assembly with 3 star screws. The ballast has its own electrical plug that plugs directly into the overall headlight assembly. There is presumably another wiring harness inside the overall headlight assembly. The ballast/control unit is believed to contain a condenser and switching relays, and when mine failed on my 4th headlight failure, I could hear relay clicking in the headlight area and saw the headlight blinking. It went bad over time and only blinked sometimes, and then later nothing but blinking. The high beam worked for a while and then started blinking also in the same headlight. Presumably, there are separate relays in the ballast for the high and low beams. Clicking and blinking was also taking place for both the bulb and igniter/transformer failures and so we would further presume that the control unit in the ballast senses some types of bulb and/or igniter failures and cycles the relays in the ballast which serves to blink the headlights. Unlike fluorescent lights in your house, one of the 3 units has to be doing the dc to ac conversion. The DC to AC conversion is either being done in the igniter or the ballast/control unit, I would guess it is being done in the ballast/control unit.
They are nice looking cars and the xenon headlights are extra special bright, and so I figure they are worth the trouble.
They are available in different wavelengths, and my current favorite is 10k bulbs that are thought to be the brightest. I am still running a 6k bulb on the other side. Mine have gone out a few times. The bulbs are 2 for $10 on EBay.
Based on VIN number, Autohaus in Northbrook, IL says that my 2002 ML320 was sold with the following Xenon parts, although the parts are usually sold for the 2003-2008 models. Some Mercedes dealers will give you the parts numbers and others have wised up and won't because they have found that giving you the parts numbers makes it too easy for you to search for parts cheap Chinese knock off and/or bootleg parts at lower cost on EBay.com.
Description, OEM Price, OEM Part No., Remark, EBay price
igniter/transformer, $182 OEM, 0028202526, plugs into bulb, $36 EBay, is thought to contain a 12 Vac to 77 Vac step up transformer for Xenox bulbs
control unit/ballast, $545 OEM, 0028202326, capacitor and relays, $26 EBay, it's thought to contain a capacitor to fire arc, relays, control logic, DC to AC
bulb, $140 OEM, 910139000001, bulb, 2 for $10 EBay, search for part numbers the dealer gives you for your build or try the part numbers provided above
Mercedes typically charges $170 for the diagnosis. You can replace the three parts yourself in 10 minutes.
EBay also has a $64 kit containing all three components that presumably match. It is hardly ever the wiring or the headlight switch. There appear to be two different bulb types that look the same but are not electrically interchangeable. The first two times it was bulbs (EBay 2 for $15 at the time). The third time it was an igniter/transformer (EBay $41 at the time now $36). The 4th time was resolved this weekend when the $26 control unit/Ballast was replaced. And so I've had headlight outages at one time or another from the three most common failures (bulb, igniter, ballast) in a 130k mi 2002 ML320. The 4th time, both the high and low beam was blinking on the right side. I replaced the bulb and igniter/transformer and that didn't stop the blinking. Replacing the ballast stopped the blinking the 4th time the headlights experienced a failure.
So far, it has been a lot like working on florescent lights in your house which have the same 3 parts on the old style units. A pattern has developed. It is easy to work on these headlights. You remove the entire headlight assembly with 1 screw top side and two nuts along the bottom. There is a hinged swinging plastic part under the headlight that conceals the bottom two headlight bolts. One side of the hinged swinging plastic part under the headlight is clipped to the grill. You unfasten the clip, swing the plastic cover to the side and unfasten the three headlight assembly screws. That swinging cover is a fairly delicate piece and you can remove it entirely by pushing towards the vehicle on the center of the hinge to remove the center plastic hinge piece and then pushing in slightly on the outer hinged side in a circular motion in and then towards the center of the grill with zero force, you are merely guiding it off. Otherwise, you break the hinged part or chip the paint off the corner of the fender. And the paint does chip and the fender does start rusting there if you try to bully it off. Once you have the headlight assembly off, a simple plastic cover on the rear of the headlight assembly is unsnapped to expose the igniter. On the right side, the igniter and bulb can be replaced without removing the overall headlight assembly, but it would probably take some experience with all the plastic parts to get them off without breaking them. You'll be happier removing the entire headlight assembly. On the driver side, forget about going half way because there is not enough room to pull the igniter cover off the headlight assembly without removing the headlight assembly. When reinstalling the headlight assembly, sit on the ground and focus 90% of your attention on making a centered alignment of the two bottom posts in the headlight assembly. If you do it the other way and focus on the top of the headlight assembly, the top snap goes in and one of the bottom posts might have missed the holes and the top plastic tab on the top of the headlight assembly is nearly impossible to release again without breaking off the plastic tab. It is hard to say if their engineers are just plain stupid, or they designed it that way to sell more headlight assemblies. I'm pretty sure that the headlight will stay on just fine with that top plastic snap broken off as long as you still have the top screw hole intact.
The igniter/transformer is removed by pushing in a little and twisting 1/16 of a turn in the indicated direction. Don't force it because the little plastic prongs break off and render the igniter useless. If you try to use an igniter with a prong missing, the high resistance connection melts the igniter to the bulb and you lose them both as a best case scenario, and start a fire worse case scenario. There is a sticker on the igniter that indicates direction to twist on/off. There are a couple of metal wire clips that are unsnapped to remove the bulb. Use gloves and don't touch the bulb and leave hand oil on it or it won't work for long. The ballast is a relatively flat 3" x 4" x 3/4" cast metal box that is attached to the bottom of the headlight assembly with 3 star screws. The ballast has its own electrical plug that plugs directly into the overall headlight assembly. There is presumably another wiring harness inside the overall headlight assembly. The ballast/control unit is believed to contain a condenser and switching relays, and when mine failed on my 4th headlight failure, I could hear relay clicking in the headlight area and saw the headlight blinking. It went bad over time and only blinked sometimes, and then later nothing but blinking. The high beam worked for a while and then started blinking also in the same headlight. Presumably, there are separate relays in the ballast for the high and low beams. Clicking and blinking was also taking place for both the bulb and igniter/transformer failures and so we would further presume that the control unit in the ballast senses some types of bulb and/or igniter failures and cycles the relays in the ballast which serves to blink the headlights. Unlike fluorescent lights in your house, one of the 3 units has to be doing the dc to ac conversion. The DC to AC conversion is either being done in the igniter or the ballast/control unit, I would guess it is being done in the ballast/control unit.
Last edited by ghinshaw; 01-14-2019 at 12:44 PM.
01-16-2019, 05:55 PM
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2002 ML320, 2006 CLK350, 2015 ML350, 2012 CTS4, 69 Z28, 87 C4
I would imagine the celebration would be short lived if you read the longest post in this thread, get the part number, used the part number to search on EBay, and find out the part is less than $50 new on EBay..
05-16-2021, 05:16 PM
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2002 ML320, 2006 CLK350, 2015 ML350, 2012 CTS4, 69 Z28, 87 C4
Doesn't sound like me.
Why would I recommend paying $50 for a $25 part:
https://www.ebay.com/itm/28406895169...oAAOSwkEJfo6Yr
That part is hiding. When you pull out the entire headlight assembly, you find it bolted onto the bottom of the assembly.
It is the last of the 3 parts that I think about, and I only shotgun it when replacing the bulb and transformer hasn't netted a working unit.
I haven't had to work on those headlights again since I wrote the original post and the car has been working fine ever since.
Volvo has a 90k mile service that replaces a bunch of random parts. With the ML320 I replaced the parts one at a time as they died.
Why would I recommend paying $50 for a $25 part:
https://www.ebay.com/itm/28406895169...oAAOSwkEJfo6Yr
That part is hiding. When you pull out the entire headlight assembly, you find it bolted onto the bottom of the assembly.
It is the last of the 3 parts that I think about, and I only shotgun it when replacing the bulb and transformer hasn't netted a working unit.
I haven't had to work on those headlights again since I wrote the original post and the car has been working fine ever since.
Volvo has a 90k mile service that replaces a bunch of random parts. With the ML320 I replaced the parts one at a time as they died.
