Bimmer Jon and I have been working together to figure out how you retrofit auto headlights into a 2001 or older e46. Through our research we have discovered the following:
Prior to 9/2001 you could buy auto rain wipers, which sense how much rain is falling and regulate your windshield wiper speeds accordingly. You can tell if you have a rain sensor equipped car by looking at the top middle of the windscreen and if it's equipped with this rain sensor it looks like this:
Subsequent to 9/2001 BMW added an auto headlight feature, which turns your headlights on when it's dark and off when it's light. These cars are equipped with a rain and light sensor, which is different than just a rain sensor, and a light control module with an automatic headlight setting. The difference can be seen here (item number 1): http://www.realoem.com/bmw/showparts.do?model=AV53&mospid=47725&btnr=61_0169&hg=61&fg=15&hl=7
The wiring and connectors are the same for both.
The electronic box that feeds these signals to the Light Control Module is attached to the window with two clips, with slight differences between the rain sensor and the rain and light sensor. What makes it impractical to just change out the sensor is the fact that the receptors are glued to the windshield, and are not interchangeable. The rain sensor looks like this:
The rain and light sensor looks like this:
So, your options if you're trying to retrofit auto headlights onto your pre-9/2001 E46 are to unglue the receptor from the windscreen and glue on the new receptor, or to install a windshield with the new receptor attached. After that, it's a matter of installing a new light control module with the auto headlight setting and having the car recoded to work with your new sensors.
At this time, I'm waiting until I get a new windshield, at which time I'll get one with the rain and light sensor receptors.
Prior to 9/2001 you could buy auto rain wipers, which sense how much rain is falling and regulate your windshield wiper speeds accordingly. You can tell if you have a rain sensor equipped car by looking at the top middle of the windscreen and if it's equipped with this rain sensor it looks like this:
Subsequent to 9/2001 BMW added an auto headlight feature, which turns your headlights on when it's dark and off when it's light. These cars are equipped with a rain and light sensor, which is different than just a rain sensor, and a light control module with an automatic headlight setting. The difference can be seen here (item number 1): http://www.realoem.com/bmw/showparts.do?model=AV53&mospid=47725&btnr=61_0169&hg=61&fg=15&hl=7
The wiring and connectors are the same for both.
The electronic box that feeds these signals to the Light Control Module is attached to the window with two clips, with slight differences between the rain sensor and the rain and light sensor. What makes it impractical to just change out the sensor is the fact that the receptors are glued to the windshield, and are not interchangeable. The rain sensor looks like this:
The rain and light sensor looks like this:
So, your options if you're trying to retrofit auto headlights onto your pre-9/2001 E46 are to unglue the receptor from the windscreen and glue on the new receptor, or to install a windshield with the new receptor attached. After that, it's a matter of installing a new light control module with the auto headlight setting and having the car recoded to work with your new sensors.
At this time, I'm waiting until I get a new windshield, at which time I'll get one with the rain and light sensor receptors.