Car Door Laser Logo Projectors Modding

It is possible to buy courtesy light replacements with logo projection from AliExpress for less than 10€. While some of them mention the word "laser", they are actually based on high power Cree LEDs.

If you are buying these lights, I highly recommend opening them up and have a look inside. In my case the LED module was not glued to the heatsink. I had to use adhesive heatsink paste to glue the LED onto the heatsink. The glue I used was sold as "Thermal Conductive Heatsink Plaster". You can see the plaster under the led module in the picture above.

I also found out that the LED driver is set to give out 500mA constant current and this roughly equals to 5W in this case. This is simply too much power and causes LED to get too hot and burn out. When I was working in the car, I left the door open for a long period and this caused Cree LED to burn out. The LED driver is a pretty small module and the current output can be changed by replacing a SMD resistor. I didn't have SMD resistors so I found a replacement module which gives about 300mA output. This module sold as MR16 3W LED Driver. Of course the brightness went down about 20% but the LED module is not getting too hot anymore (at least it will take much longer time for it to get to a critical temperature)

In addition, I didn't like the fact that these replacement courtesy lights only point downwards and they do not have the red light warning for incoming cars. So I have embedded two red leds in parallel to the Cree LEDs. You will need to figure out which size resistors you need or use special LEDs if you do this. I found out some strange LEDs which could be wired directly to 12V. They work reasonably well in this setup because Cree LED's input floats getween 3V - 5V.

One last thing to mention is that usually these items come with no real connectors. Only some models of them are with real connectors. While you can just slide the provided pins into the connector of the car. They will simply get out in time and it does not look safe at all. I have found out some connectors which were exactly same as on my original courtesy lights on AliExpress and crimped them.

Here is what the end result looks like, powered from portable lead acid battery.