This 2004 Volvo XC 90 came in with the driver’s side headlight not working. This particular vehicle has HID headlights.
There are two retaining bars that hold the light assembly in place.
They simply lift and slide out of the slots in the rear of the headlight assembly. There are slight detents but it takes a minimal amount of force to lift the bars up. Do take note of the yellow warning label. This is a high voltage system that can cause bodily harm or even death. Make sure the system is off before working with the system.
With the retaining or locking bars removed the light assembly will wiggle loose from it’s perch. I recommend using a soft cloth to lay under the lens area when the light assembly is inverted.
The large round cover will twist counter clock wise.
After it has been turn to it’s stopping point the cover will lift off.
It takes a little coordination and finger strength to remove the connector from the silver ballast assembly. I tried lifting the ballast/bulb assembly out before unplugging the connector but found it more difficult.
Now that the harness is disconnected I can turn my attention back to removing the ballast/bulb assembly. Note the wire retainer that holds the assembly down.
Each end of the wire retainer needs to be unhooked from hold down bars. Then the two ends can be lifted and rotated back to get the retaining wire assembly out of the way.
Although I am not doing a great job of it in the next picture try to lift the assembly as straight as possible. Also remember to not touch the glass portion of the light assembly with your fingers. If the old bulb is blown, there will be no detriment to the bulb if you do touch it. However I feel it is good practice to get the feel of removal and installation without touching the glass. It will get you prepared for the real deal of installing the expensive new bulb. I actually remove and install the assembly several times to make sure I can do it without error.
Note the position of the notches in the black plastic ring of the bulb. The new bulb must be oriented in the same position. If not the assembly cannot be properly installed in the headlight assembly. I am sure you can guess how I know that. Hold the ballast base with one hand and grasp the plastic ring on the bulb base. Rotate it counter clock wise. There are some detents rotate past. Once the bulb base will rotate no more, pull the bulb from the ballast. Only by holding the plastic base though. Reverse the procedure to install the new bulb in the ballast base. Make sure it is fully installed. You should feel a slight click as the bulb is rotated to it’s stopping point.
If you click on and enlarge the next pictures you should be able to see the hairline cracks in the glass. The cracks allow the inert Xenon gas to escape and the subsequent bulb failure.
Make sure the assembly goes in fully. It should take some effort to hook the retaining wires but it should not be excessive. The wire retainer may become dislodged and fall out somewhere in the process but do not be alarmed. Just make sure it is fully hooked at all four contact points.
Put it all back together and we now have light.
It is a bit of a guessing game on determining if the bulb is blown or if the ballast is faulty. I am not a fan of inserting individual test leads into small high voltage connectors. The cracks in the glass are a fair indicator of a blown bulb. For good measure though I removed the other light assembly (it was working). I then took the bulb only, not the ballast and installed it in the ballast and assembly in question. It all worked so I knew that changing the bulb only would fix this problem.