There were no top lights in my BESTURN B50 and my wife always complained that my car was like Black Hole at night, which resulted in this LED lights DIY. I always admired those skillful hands that could create something from nothing. This time, I decided to do something myself instead of being an envier. Top lights assembly, 100 pieces of 5050 white color LED lights from bestlightingbuy.com and hole plates would be enough. There was a chance for great error if just cut ceiling board. So I decided to cut hardboard as a mould. But it was not as good as I thought when I cut off ceiling board. The part which I took off happened to be where the girder was. Top light was pushed by girder, leaving 2mm gap.
Two pieces of PCB
Do some foundation works.
Then weld LED on PCB.
I planned to connect 3 resistors in parallel.
I did a test: it was 12.5V when the engine did not work; it was 124.44V when I started the engine; and it was still 14.44V even when engine rotated 5000 time per minute. So I considered taking 14.44V as the value of current-limiting resistors.
It worked. But those resistors were increasingly hot after a couple of minutes. It was 73 Ohm when 3 pieces of 220 Ohm resistors connected in parallel.
Another test with 100 Ohm resistors (0.5W) and 56 Ohm resistors (0.5W). It came out that 56 Ohm resistors did a great job in heating.
Hot melt adhesive was a very necessary part. Because coating film on reflective bowls was conductive. Make sure every part was covered.
2 pieces of 56 Ohm resistors (0.5W) connected in series.
Put LED lights into assembly.
Charge with electricity.
Let’s turn to the lights at back seats.
This was how it looked like if it was finished.
I was quite proud of myself when I saw what I did.
Do the welding.
Because of lacking of 56 Ohm resistors, I had to put 2 pieces of 220 Ohm resistors in parallel, almost equalling to 2 pieces 56 Ohm resistors in series.
As soon as the lights done, I started with paper mould.
Draw up exactly the length and width of top lights.
Cut the part out.
This was how it looked like at back.
Connect with wires: I planned to weld those wires with PCB. Later, I realized welding did not work for it. Electrical contacts did not hold Tin. That left me no choice but clipping wires with contacts and covering with hot melt adhesive.
Oops! The part which I chose happened to be where the girder was.
The gap made me very uncomfortable.
Actually, it wasn’t that bad.