Trying to find out what a component is on my 2006 TL. My son recently ran front left of car into a pole. No frame damage and we were able to fix it ourselves with used parts (fender, bumper, headlight). When plugging in all the connectors for the headlight, we had an extra connector that is very similar to the ones for the headlight. We found a small device in the damaged parts that matches the connector, but I’m not sure what it is. It’s a small black box about the size of the horn, but it’s not the horn.
Can anyone tell me what it is and where it supposed to mount?

 

First guess would be the ballast unit for HID lamps. See Ballast & ignitor for some images. The components may differ depending on the manufacturer.

Can you post a picture?